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Encyclopedia > Plant breeding

Plant breeding is the purposeful manipulation of plant species in order to create desired genotypes and phenotypes for specific purposes. This manipulation involves either controlled pollination, genetic engineering, or both, followed by artificial selection of progeny. Plant breeding often, but not always, leads to plant domestication. The genotype is the specific genetic makeup (the specific genome) of an individual, usually in the form of DNA. It codes for the phenotype of that individual. ... The phenotype of an individual organism is either its total physical appearance and constitution, or a specific manifestation of a trait, such as size or eye color, that varies between individuals. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... An iconic image of genetic engineering; this autoluminograph from 1986 of a glowing transgenic tobacco plant bearing the luciferase gene, illustrating the possibilities of genetic engineering. ... This Chihuahua mix and Great Dane show the wide range of dog breed sizes created using artificial selection. ... Progeny can mean: A genetic descendant, see offspring. ... Dogs and sheep were among the first animals to be domesticated. ...


Plant breeding has been practiced for thousands of years, since near the beginning of human civilization. It is now practiced worldwide by government institutions and commercial enterprises. International development agencies believe that breeding new crops is important for ensuring food security and developing practices through the development of crops suitable for their environment Subsistence farmers with a Treadle Pump. ...

Contents

Domestication

This map shows the sites of domestication for a number of crops. Places where crops were initially domesticated are called centres of origin
Main article: Domestication

Domestication of plants is an artificial selection process conducted by humans to produce plants that have fewer undesirable traits of wild plants, and which renders them dependent on artificial (usually enhanced) environments for their continued existence. The practice is estimated to date back 9,000-11,000 years. Many crops in present day cultivation are the result of domestication in ancient times, about 5,000 years ago in the Old World and 3,000 years ago in the New World. In the Neolithic period, domestication took a minimum of 1,000 years and a maximum of 7,000 years. Today, all of our principal food crops come from domesticated varieties. Centers of origin of selected crops, compiled by the USDA general accounting office File links The following pages link to this file: Plant breeding Categories: Department of Agriculture images ... Centers of origin of selected crops, compiled by the USDA general accounting office File links The following pages link to this file: Plant breeding Categories: Department of Agriculture images ... Dogs and sheep were among the first animals to be domesticated. ... Dogs and sheep were among the first animals to be domesticated. ... This Chihuahua mix and Great Dane show the wide range of dog breed sizes created using artificial selection. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: wise man or knowing man) in the family Hominidae (the great apes). ... The Old World consists of those parts of Earth known to Europeans, Asians, and Africans before the voyages of Christopher Columbus; it includes Europe, Asia, and Africa (collectively known as Africa-Eurasia), plus surrounding islands. ... Frontispiece of Peter Martyr dAnghieras De orbe novo (On the New World). Carte dAmérique, Guillaume Delisle, 1722. ... An array of Neolithic artifacts, including bracelets, axe heads, chisels, and polishing tools. ...


A cultivated crop species that has evolved from wild populations due to selective pressures from traditional farmers is called a landrace. Landraces, which can be the result of natural forces or domestication, are plants (or animals) that are ideally suited to a particular region or environment. An example are the landraces of rice, Oryza sativa subspecies indica, which was developed in South Asia, and Oryza sativa subspecies japonica, which was developed in China. The hierarchy of scientific classification. ... For other uses, see Farmer (disambiguation). ... Landrace refers to a race of animals or plants ideally suited for the land (environment) in which they live and, in some cases, work; they often develop naturally with minimal assistance or guidance from humans (or from humans using traditional rather than modern breeding methods), hence are usually older, less... For other uses, see Animal (disambiguation). ... This article needs additional references or sources for verification. ... This article is about the zoological term. ... Map of South Asia (see note on Kashmir). ...


Classical plant breeding

Classical plant breeding uses deliberate interbreeding (crossing) of closely or distantly related individuals to produce new crop varieties or lines with desirable properties. Plants are crossbred to introduce traits/genes from one variety or line into a new genetic background. For example, a mildew-resistant pea may be crossed with a high-yielding but susceptible pea, the goal of the cross being to introduce mildew resistance without losing the high-yield characteristics. Progeny from the cross would then be crossed with the high-yielding parent to ensure that the progeny were most like the high-yielding parent, (backcrossing). The progeny from that cross would then be tested for yield and mildew resistance and high-yielding resistant plants would be further developed. Plants may also be crossed with themselves to produce inbred varieties for breeding. In biology, a trait or character is a genetically inherited feature of an organism. ... For a non-technical introduction to the topic, see Introduction to Genetics. ... Mildew is a grey, mold-like growth caused by one of two different types of micro-organisms. ... Binomial name Pisum sativum L. A pea is the small, edible round green bean which grows in a pod on the leguminous vine Pisum sativum, or in some cases to the immature pods. ...


Classical breeding relies largely on homologous recombination between chromosomes to generate genetic diversity. The classical plant breeder may also makes use of a number of in vitro techniques such as protoplast fusion, embryo rescue or mutagenesis (see below) to generate diversity and produce hybrid plants that would not exist in nature. Genetic recombination is the process by which a strand of DNA is broken and then joined to the end of a different DNA molecule. ... Genetic diversity is a characteristic of ecosystems and gene pools that describes an attribute which is commonly held to be advantageous for survival -- that there are many different versions of otherwise similar organisms. ... “Natural” redirects here. ...

The Yecoro wheat (right) cultivar is sensitive to salinity, plants resulting from a hybrid cross with cultivar W4910 (left) show greater tolerance to high salinity
The Yecoro wheat (right) cultivar is sensitive to salinity, plants resulting from a hybrid cross with cultivar W4910 (left) show greater tolerance to high salinity

Traits that breeders have tried to incorporate into crop plants in the last 100 years include: Wheat selection Exposure to high salinity is killing Yecoro Rojo (right), a wheat cultivar that has moderate salt tolerance. ... Wheat selection Exposure to high salinity is killing Yecoro Rojo (right), a wheat cultivar that has moderate salt tolerance. ... Species T. aestivum T. boeoticum T. compactum T. dicoccoides T. dicoccon T. durum T. monococcum T. spelta T. sphaerococcum T. timopheevii References:   ITIS 42236 2002-09-22 For the indie rock group see: Wheat (band). ... This Osteospermum Pink Whirls is a successful cultivar. ...

  1. Increased quality and yield of the crop
  2. Increased tolerance of environmental pressures (salinity, extreme temperature, drought)
  3. Resistance to viruses, fungi and bacteria
  4. Increased tolerance to insect pests
  5. Increased tolerance of herbicides

For the Talib Kweli album Quality (album) Quality can refer to a. ... Yield may mean: In economics, yield is a measure of the amount of income an investment generates over time (related to return on investment). ... In physiology, tolerance occurs when an organism builds up a resistance to the effects of a substance after repeated exposure. ... Annual mean sea surface salinity for the World Ocean. ... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... Fields outside Benambra, Victoria suffering from drought conditions A drought is an extended period of months or years when a region notes a deficiency in its water supply. ... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (from the Latin noun virus, meaning toxin or poison) is a microscopic particle (ranging in size from 20 - 300 nm) that can infect the... Subkingdom/Phyla Chytridiomycota Blastocladiomycota Neocallimastigomycota Glomeromycota Zygomycota Dikarya (inc. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Monura - extinct Subclass Pterygota Infraclass Paleoptera (may be paraphyletic) Ephemeroptera (mayflies) Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Diaphanopterodea - extinct Protodonata - extinct Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Caloneurodea - extinct Titanoptera - extinct Protorthoptera - extinct Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera... A herbicide is a pesticide used to kill unwanted plants. ...

Before World War II

Intraspecific hybridization within a plant species was demonstrated by Charles Darwin and Gregor Mendel, and was further developed by geneticists and plant breeders. In the early 20th century, plant breeders realized that Mendel's findings on the non-random nature of inheritance could be applied to seedling populations produced through deliberate pollinations to predict the frequencies of different types. // This article is about a biological term. ... For other people of the same surname, and places and things named after Charles Darwin, see Darwin. ... Gregor Johann Mendel (July 20, 1822[1] – January 6, 1884) was a Moravian[2] Augustinian priest and scientist often called the father of modern genetics for his study of the inheritance of traits in pea plants. ... A geneticist is a scientist who studies genetics, the science of heredity and variation of organisms. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999... Mendelian inheritance (or Mendelian genetics or Mendelism) is a set of primary tenets relating to the transmission of hereditary characteristics from parent organisms to their children; it underlies much of genetics. ... Sunflower seedlings, just three days after germination In a botanical sense, germination is the process of emergence of growth from a resting stage. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ...


In 1908, George Harrison Shull described heterosis, also known as hybrid vigor. Heterosis describes the tendency of the progeny of a specific cross to outperform both parents. The detection of the usefulness of heterosis for plant breeding has led to the development of inbred lines that reveal a heterotic yield advantage when they are crossed. Maize was the first species where heterosis was widely used to produce hybrids. 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar). ... George Harrison Shull (April 15, 1874 - September 28, 1954) was an American geneticist. ... Heterosis is increased strength of different characteristics in hybrids; the possibility to obtain a better individual by combining the virtues of its parents. ... “Corn” redirects here. ...


By the 1920s, statistical methods were developed to analyze gene action and distinguish heritable variation from variation caused by environment. In 1933, another important breeding technique, cytoplasmic male sterility (CMS), developed in maize, was described by Marcus Morton Rhoades. CMS is a maternally inherited trait that makes the plant produce sterile pollen. This enables the production of hybrids without the need for labour intensive detasseling. The 1920s is a decade that is sometimes referred to as the Jazz Age or the Roaring Twenties, usually applied to America. ... A graph of a normal bell curve showing statistics used in educational assessment and comparing various grading methods. ... 1933 (MCMXXXIII) was a common year starting on Sunday. ... Male sterility is defined as the failure of plants to produce functional anthers, pollen, or male gametes. ... Marcus Morton Rhoades (July 23, 1903 - December 30, 1991) was an American cytogeneticist, his research on maize led to important discoveries for basic genetics and the applied science of plant breeding. ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ... Detasseling is the act of removing the pollen-producing tassel from a corn (maize) plant. ...


These early breeding techniques resulted in large yield increase in the United States in the early 20th century. Similar yield increases were not produced elsewhere until after World War II, the Green Revolution increased crop production in the developing world in the 1960s. Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... The Green Revolution is a term used to describe the transformation of agriculture in many developing nations that led to significant increases in agricultural production between the 1940s and 1960s. ...


After World War II

Following World War II a number of techniques were developed that allowed plant breeders to hybridize distantly related species, and artificially induce genetic diversity. Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000...


When distantly related species are crossed, plant breeders make use of a number of plant tissue culture techniques to produce progeny from otherwise fruitless mating. Interspecific and intergeneric hybrids are produced from a cross of related species or genera that do not normally sexually reproduce with each other. These crosses are referred to as Wide crosses. For example, the cereal triticale is a wheat and rye hybrid. The cells in the plants derived from the first generation created from the cross contained an uneven number of chromosomes and as result was sterile. The cell division inhibitor colchicine was used to double the number of chromosomes in the cell and thus allow the production of a fertile line. Plant tissue culture, also called micropropagation, is a practice used to propagate plants under sterile conditions, often to produce clones of a plant. ... For other uses, see Reproduction (disambiguation) Reproduction is the biological process by which new individual organisms are produced. ... This article is about cereals in general. ... Triticale Triticale (x Triticosecale) is an artificial or man-made hybrid of rye and wheat first bred in laboratories during the late 19th century. ... Species T. aestivum T. boeoticum T. compactum T. dicoccoides T. dicoccon T. durum T. monococcum T. spelta T. sphaerococcum T. timopheevii References:   ITIS 42236 2002-09-22 For the indie rock group see: Wheat (band). ... Binomial name Secale cereale M.Bieb. ... This does not adequately cite its references or sources. ... Colchicine is a highly deadly poisonous alkaloid, originally extracted from plants of the genus Colchicum (Autumn crocus, also known as the Meadow saffron). Originally used to treat rheumatic complaints and especially gout, it was also prescribed for its cathartic and emetic effects. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the...


Failure to produce a hybrid may be due to pre- or post-fertilization incompatibility. If fertilization is possible between two species or genera, the hybrid embryo may abort before maturation. If this does occur the embryo resulting from an interspecific or intergeneric cross can sometimes be rescued and cultured to produce a whole plant. Such a method is referred to as Embryo Rescue. This technique has been used to produce new rice for Africa, an interspecific cross of Asian rice (Oryza sativa) and African rice (Oryza glaberrima). Categories: Biology stubs ... For other uses, see Embryo (disambiguation). ... New Rice for Africa is an interspecific cultivar of rice developed by the West Africa Rice Development Association (WARDA) to improve the yield of African rice varieties. ...


Hybrids may also be produced by a technique called protoplast fusion. In this case protoplasts are fused, usually in an electric field. Viable recombinants can be regenerated in culture. Initially protoplast (in Greek: proton = first and platho = mould) referred to the first organized body of a species this meaning is similar to the non-biological definition, the first from from which all subsequent forms are derived. ...


Chemical mutagens like EMS and DMS, radiation and transposons are used to generate mutants with desirable traits to be bred with other cultivars. Classical plant breeders also generate genetic diversity within a species by exploiting a process called somaclonal variation, which occurs in plants produced from tissue culture, particularly plants derived from callus. Induced polyploidy, and the addition or removal of chromosomes using a technique called chromosome engineering may also be used. In biology, a mutagen (Latin, literally origin of change) is a physical or chemical agent that changes the genetic information (usually DNA) of an organism and thus increases the number of mutations above the natural background level. ... Ethyl methanesulfonate is a mutagenic, teratogenic, and possibly carcinogenic organic compound with formula C3H8O3S and CAS number 62-50-0. ... Dimethyl sulfate has chemical formula (CH3)2SO4. ... Radiation as used in physics, is energy in the form of waves or moving subatomic particles. ... Transposons are sequences of DNA that can move around to different positions within the genome of a single cell, a process called transposition. ... It has been suggested that this article or section be merged into mutation. ... This Osteospermum Pink Whirls is a successful cultivar. ... Somaclonal variation is the term used to describe the variation seen in plants that have been produced by plant tissue culture. ... Plant tissue culture, also called micropropagation, is a practice used to propagate plants under sterile conditions, often to produce clones of a plant. ... Polyploidy refers to cells or organisms that contain more than two copies of each of their chromosomes. ...


When a desirable trait has been bred into a species, a number of crosses to the favoured parent are made to make the new plant as similar to the favored parent as possible. Returning to the example of the mildew resistant pea being crossed with a high-yielding but susceptible pea, to make the mildew resistant progeny of the cross most like the high-yielding parent, the progeny will be crossed back to that parent for several generations (See backcrossing ). This process removes most of the genetic contribution of the mildew resistant parent. Classical breeding is therefore a cyclical process. In plant breeding, backcrossing is a crossing of a hybrid with one of its parents. ...


It should be noted that with classical breeding techniques, the breeder does not know exactly what genes have been introduced to the new cultivars. Some scientists therefore argue that plants produced by classical breeding methods should undergo the same safety testing regime as genetically modified plants. There have been instances where plants bred using classical techniques have been unsuitable for human consumption, for example the poison solanine was unintentionally increased to unacceptable levels in certain varieties of potato though plant breeding. New potato varieties are often screened for solanine levels before reaching the marketplace. This article does not cite any references or sources. ... An iconic image of genetic engineering; this autoluminograph from 1986 of a glowing transgenic tobacco plant bearing the luciferase gene, illustrating the possibilities of genetic engineering. ... The skull and crossbones symbol (Jolly Roger) traditionally used to label a poisonous substance. ... Solanine is a glycoalkaloid poison found in species of the nightshade family. ... For other uses, see Potato (disambiguation). ...


Modern plant breeding

Modern plant breeding uses techniques of molecular biology to select, or in the case of genetic modification, to insert, desirable traits into plants.


Marker-Assisted Selection

Sometimes many different genes can influence a desirable trait in plant breeding. The use of tools such as molecular markers or DNA fingerprinting can map thousands of genes. This allows plant breeders to screen large populations of plants for those that possess the trait of interest. THe screening is based on the presence or absence of a certain gene as determined by laboratory procedures, rather than on the visual identification of the expressed trait in the plant.


Genetic modification

See main article on Transgenic plants.

Genetic modification of plants is achieved by adding a specific gene or genes to a plant, or by knocking out a gene with RNAi, to produce a desirable phenotype. The plants resulting from adding a gene are often referred to as transgenic plants. If for genetic modification genes of the species or of a crossable plant are used under control of their native promoter, then they are called Cisgenic plants. Genetic modification can produce a plant with the desired trait or traits faster than classical breeding because the majority of the plant's genome is not altered. Transgenic plants are plants that have been genetically engineered, a breeding approach that uses recombinant DNA techniques to create plants with new characteristics. ... Genetic engineering, genetic modification (GM), and gene splicing (once in widespread use but now deprecated) are terms for the process of manipulating genes in an organism, usually outside of the organisms normal reproductive process. ... In molecular biology, RNA interference (RNAi) is a mechanism in which the presence of small fragments of double-stranded RNA (dsRNA) whose sequence matches a given gene interferes with the expression of that gene. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ... Transgenic plants are plants that have been genetically engineered, a breeding approach that uses recombinant DNA techniques to create plants with new characteristics. ...


To genetically modify a plant, a genetic construct must be designed so that the gene to be added or knocked-out will be expressed by the plant. To do this, a promoter to drive transcription and a termination sequence to stop transcription of the new gene, and the gene of genes of interest must be introduced to the plant. A marker for the selection of transformed plants is also included. In the laboratory, antibiotic resistance is a commonly used marker: plants that have been successfully transformed will grow on media containing antibiotics; plants that have not been transformed will die. In some instances markers for selection are removed by backcrossing with the parent plant prior to commercial release. A promoter is a regulatory region of DNA located upstream (towards the 5 region) of a gene, providing a control point for regulated gene transcription. ... A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... This article does not cite any references or sources. ... Antibiotic resistance is the ability of a micro-organism to withstand the effects of an antibiotic. ... In plant breeding, backcrossing is a crossing of a hybrid with one of its parents. ...


The construct can be inserted in the plant genome by genetic recombination using the bacteria Agrobacterium tumefaciens or A. rhizogenes, or by direct methods like the gene gun or microinjection. Using plant viruses to insert genetic constructs into plants is also a possibility, but the technique is limited by the host range of the virus. For example, Cauliflower mosaic virus (CaMV) only infects cauliflower and related species. Another limitation of viral vectors is that the virus is not usually passed on the progeny, so every plant has to be inoculated. Genetic recombination is the process by which a strand of DNA is broken and then joined to the end of a different DNA molecule. ... Binomial name Agrobacterium tumefaciens Smith & Townsend, 1907 Synonyms Bacterium tumefaciens Smith and Townsend 1907 Pseudomonas tumefaciens (Smith and Townsend 1907) Duggar 1909 Phytomonas tumefaciens (Smith and Townsend 1907) Bergey et al. ... Binomial name Agrobacterium rhizogenes (Riker et al. ... The gene gun is a device for injecting cells with genetic information, originally designed for plant transformation. ... Microinjection refers to the process of using a micro needle to insert substances at a microscopic or borderline macroscopic level into a single living cell. ... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (from the Latin noun virus, meaning toxin or poison) is a microscopic particle (ranging in size from 20 - 300 nm) that can infect the... Cauliflower mosaic virus (CaMV) is the type member of the caulimoviruses, one of the six genera in the Caulimoviridae family, pararetroviruses that infect plants (Pringle, 1999). ... Percentages are relative to US recommendations for adults. ...


The majority of commercially released transgenic plants, are currently limited to plants that have introduced resistance to insect pests and herbicides. Insect resistance is achieved through incorporation of a gene from Bacillus thuringiensis (Bt) that encodes a protein that is toxic to some insects. For example, the cotton bollworm, a common cotton pest, feeds on Bt cotton it will ingest the toxin and die. Herbicides usually work by binding to certain plant enzymes and inhibiting their action. The enzymes that the herbicide inhibits are known as the herbicides target site. Herbicide resistance can be engineered into crops by expressing a version of target site protein that is not inhibited by the herbicide. This is the method used to produce glyphosate resistant crop plants (See Glyphosate) Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Monura - extinct Subclass Pterygota Infraclass Paleoptera (may be paraphyletic) Ephemeroptera (mayflies) Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Diaphanopterodea - extinct Protodonata - extinct Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Caloneurodea - extinct Titanoptera - extinct Protorthoptera - extinct Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera... Larval form of some beetle is damaging specimen of Sceliphron destillatorius in entomogical collection. ... A herbicide is a pesticide used to kill unwanted plants. ... Binomial name Berliner 1915 Bacillus thuringiensis is a Gram-positive, soil dwelling bacterium of the genus Bacillus. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Binomial name Helicoverpa zea (Boddie, 1850) The larva of the moth Helicoverpa zea (formerly in the genus Heliothis) is a major agricultural pest. ... It has been suggested that Roundup be merged into this article or section. ...


Genetic modification of plants that can produce pharmaceuticals (and industrial chemicals), sometimes called pharmacrops, is a rather radical new area of plant breeding. Pharmacology (in Greek: pharmacon is drug, and logos is science) is the study of how chemical substances interfere with living systems. ...


Issues and concerns

Modern plant breeding, whether classical or through genetic engineering, comes with issues of concern, particularly with regard to food crops. The question of whether breeding can have a negative effect on nutritional value is central in this respect. Although relatively little direct research in this area has been done, there are scientific indications that, by favoring certain aspects of a plant's development, other aspects may be retarded. A study published in the Journal of the American College of Nutrition in 2004, entitled Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999, compared nutritional analysis of vegetables done in 1950 and in 1999, and found substantial decreases in six of 13 nutrients measured, including 6% of protein and 38% of riboflavin. Reductions in calcium, phosphorus, iron and ascorbic acid were also found. The study, conducted at the Biochemical Institute, University of Texas at Austin, concluded in summary: "We suggest that any real declines are generally most easily explained by changes in cultivated varieties between 1950 and 1999, in which there may be trade-offs between yield and nutrient content.[1]" The updated USDA food pyramid, published in 2005, is a general nutrition guide for recommended food consumption. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Year 1950 (MCML) was a common year starting on Sunday (link will display the full calendar) of the Gregorian calendar. ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... A plate of vegetables Vegetable is a culinary term which generally refers to an edible part of a plant. ... Link title {{portal|Food} A nutrient is either a chemical element or compound used in an organisms metabolism or physiology. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Riboflavin (E101), also known as vitamin B2, is an easily absorbed micronutrient with a key role in maintaining health in animals. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number phosphorus, P, 15 Chemical series nonmetals Group, Period, Block 15, 3, p Appearance waxy white/ red/ black/ colorless Standard atomic weight 30. ... General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... This article deals with the molecular aspects of ascorbic acid. ... The University of Texas at Austin (often referred to as The University of Texas, UT Austin, UT, or Texas) is a doctoral/research university located in Austin, Texas. ... Yield may mean: In economics, yield is a measure of the amount of income an investment generates over time (related to return on investment). ...


The debate surrounding genetic modification of plants is huge, encompassing the ecological impact of genetically modified plants, the safety of genetically modified food and concepts used for safety evaluation like Substantial equivalence. The potential impact on nearby ecosystems is one of the greatest concerns associated with transgenic plants. ... Genetically Modified (GM) foods are produced from genetically modified organisms (GMO) which have had their genome altered through genetic engineering techniques. ... The phrase substantial equivalence is given to a relatively new concept used in the regulation of new foods, especially genetically modified foods, also called [recombinant DNA] (rDNA) derived foods (hereafter GM foods). ...


Plant breeders' rights is also a major and controversial issue. Today, production of new varieties is dominated by commercial plant breeders, who seek to protect their work and collect royalties through national and international agreements based in intellectual property rights. The range of related issues is complex. In the simplest terms, critics of the increasingly restrictive regulations argue that, through a combination of technical and economic pressures, commercial breeders are reducing biodiversity and significantly constraining individuals (such as farmers) from developing and trading seed on a regional level. Efforts to strengthen breeders' rights, for example, by lengthening periods of variety protection, are ongoing. Plant breeders rights, also known as plant variety rights (PVR), are intellectual property rights granted to the breeder of a new variety of plant. ... In law, particularly in common law jurisdictions, intellectual property is a form of legal entitlement which allows its holder to control the use of certain intangible ideas and expressions. ... Rainforests are among the most biodiverse ecosystems on earth Biodiversity is the variation of taxonomic life forms within a given ecosystem, biome or for the entire Earth. ...


Notes

  1. ^ Davis, D.R., Epp, M.D., and Riordan, H.D. 2004. Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999. Journal of the American College of Nutrition 23(6):669-682

References

  • Borojevic, S. 1990. Principles and Methods of Plant Breeding. Elserier, Amsterdam. ISBN 0-444-98832-7
  • McCouch, S. 2004. Diversifying Selection in Plant Breeding. PLoS Biol 2(10): e347.
  • Briggs, F.N. and Knowles, P.F. 1967. Introduction to Plant Breeding. Reinhold Publishing Corporation, New York.
  • Gepts, P. (2002). A Comparison between Crop Domestication, Classical Plant Breeding, and Genetic Engineering. Crop Science 42:1780–1790
  • The Origins of Agriculture and Crop Domestication - The Harlan Symposium
  • news@nature.com. 1999 Are non-GM crops safe?
  • Schouten, Henk J., Frans A. Krens & Evert Jacobsen Do cisgenic plants warrant less stringent oversight? Nature Biotechnology 24, 753 (2006).
  • Schouten, Henk J., Frans A Krens & Evert Jacobsen Cisgenic plants are similar to traditionally bred plants: EMBO reports 7, 750 - 753 (2006).
  • Sun, C. et al. 1998. From indica and japonica splitting in common wild rice DNA to the origin and evolution of Asian cultivated rice. Agricultural Archaeology 1998:21-29

External links


  Results from FactBites:
 
Plant breeding - Wikipedia, the free encyclopedia (1952 words)
Domestication, classical plant breeding and genetic engineering are all processes that alter the genome of a plant to enhance its qualities as a crop.
Plant breeding is practiced worldwide by government institutions and commercial enterprises.
Plants are cultured on media containing the herbicide, and eventually some natural genetic mutation will arise that enables the plant to survive in the presence of the herbicide.
Plant breeding - definition of Plant breeding in Encyclopedia (1063 words)
Genetic engineering of plants is achieved by adding a specific gene or genes to a plant, or by knocking out a gene with RNAi, to produce a desirable phenotype, the resulting plants are often referred to as transgenic plants.
The majority of commercially relased transgenic plants, commonly referred to as genetically modified organisms are currently limited to plants that have introduced resistanace to insect pests and herbicides.
Plants are cultured on media containg the herbicide, eventually some natural genetic mutation will arise that will enable the plant to survive in the presence of the herbicide.
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