Mutation breeding
Encyclopedia
Mutation breeding is the process of exposing seeds to chemicals or radiation
in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds. From 1930–2004 more than 2250 mutagenic plant varietals have been released that have been derived
either as direct mutants (70%) or from their progenie (30%). Crop plants account for 75% of released mutagenic species with the remaining 25% ornamentals or decorative plants. However, it is unclear how many of these varieties are currently used in agricultural production around the world, as these seeds are not always identified or labeled as being mutagenic or having a mutagenic provenance.
, radiation
and transposons are used to generate mutants. Mutation breeding is commonly used to produce traits in crops such as larger seeds, new colors, or sweeter fruits, that either cannot be found in nature or have been lost during evolution.
used X-rays on barley seeds. The resulting plants were white, yellow, pale yellow and some had white stripes. During the period 1930–2004 Gamma rays were employed to develop 64% of the radiation-induced mutant varieties, followed by X-rays (22%).
Radiation breeding may take place in atomic gardens
; and seeds have been sent into orbit in order to expose them to more cosmic radiation.
. One of the ideas was to bombard plants with radiation and produce lots of mutations, some of which, it was hoped, would lead to plants that bore more heavily or were disease or cold-resistant or just had unusual colors. The experiments were mostly conducted in giant gamma gardens on the grounds of national laboratories in the US but also in Europe and countries of the former USSR."
, the use of transgenic processes is often compared and contrasted with mutagenic processes. While the abundance and variation of transgenic organisms in human food systems, and their affect on agricultural biodiversity, ecosystem health and human health is somewhat well documented, mutagenic plants and their role on human food systems is less well known, with one journalist writing "Though poorly known, radiation breeding has produced thousands of useful mutants and a sizable fraction of the world’s crops...including varieties of rice, wheat, barley, pears, peas, cotton, peppermint, sunflowers, peanuts, grapefruit, sesame, bananas, cassava and sorghum." Mutagenic varieties tend to be made freely available for plant breeding, in contrast to many commercial plant varieties or germplasm that increasingly have restrictions on their use such as terms of use, patents and proposed Genetic user restriction technologies and other intellectual property
regimes and modes of enforcement.
‘Co4’, ‘Dhauli’ (TT9E), ‘Pant moong-1’ blackgram (YMC], [(Yellow mosaic virus) resistance)
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds. From 1930–2004 more than 2250 mutagenic plant varietals have been released that have been derived
either as direct mutants (70%) or from their progenie (30%). Crop plants account for 75% of released mutagenic species with the remaining 25% ornamentals or decorative plants. However, it is unclear how many of these varieties are currently used in agricultural production around the world, as these seeds are not always identified or labeled as being mutagenic or having a mutagenic provenance.
Process
There are different kind of mutagenic breeding such as using Chemical mutagens like EMS and DMSDimethyl sulfate
Dimethyl sulfate is a chemical compound with formula 2SO2. As the diester of methanol and sulfuric acid, its formula is often written as 2SO4 or even Me2SO4, where CH3 or Me is methyl...
, radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
and transposons are used to generate mutants. Mutation breeding is commonly used to produce traits in crops such as larger seeds, new colors, or sweeter fruits, that either cannot be found in nature or have been lost during evolution.
Radiation breeding
Exposing plants to radiation is sometimes called radiation breeding and is a sub class or mutagenic breeding. Radiation breeding was was discovered in the 1920s when Lewis J. Stadler of the University of MissouriUniversity of Missouri
The University of Missouri System is a state university system providing centralized administration for four universities, a health care system, an extension program, five research and technology parks, and a publishing press. More than 64,000 students are currently enrolled at its four campuses...
used X-rays on barley seeds. The resulting plants were white, yellow, pale yellow and some had white stripes. During the period 1930–2004 Gamma rays were employed to develop 64% of the radiation-induced mutant varieties, followed by X-rays (22%).
Radiation breeding may take place in atomic gardens
Atomic gardening
Atomic gardens are a form of mutation breeding where plants are exposed to radioactive sources, typically Cobalt-60, in order to generate useful mutations...
; and seeds have been sent into orbit in order to expose them to more cosmic radiation.
History
According to garden historian Paige Johnson "After WWII, there was a concerted effort to find 'peaceful' uses for atomic energyAtomic energy
Atomic energy is energy produced by atoms.*Nuclear energy, the energy resulting from potential differences in the nuclear force*Nuclear reaction, a process in which nuclei or nuclear particles interact, resulting in products different from the initial ones; see also nuclear fission and nuclear...
. One of the ideas was to bombard plants with radiation and produce lots of mutations, some of which, it was hoped, would lead to plants that bore more heavily or were disease or cold-resistant or just had unusual colors. The experiments were mostly conducted in giant gamma gardens on the grounds of national laboratories in the US but also in Europe and countries of the former USSR."
Comparison to other agronomic techniques
In the debate over Genetically Modified foodsGenetically modified food controversies
The genetically modified foods controversy is a dispute over the relative advantages and disadvantages of genetically modified food crops and other uses of genetically-modified organisms in food production. The dispute involves biotechnology companies, governmental regulators, non-governmental...
, the use of transgenic processes is often compared and contrasted with mutagenic processes. While the abundance and variation of transgenic organisms in human food systems, and their affect on agricultural biodiversity, ecosystem health and human health is somewhat well documented, mutagenic plants and their role on human food systems is less well known, with one journalist writing "Though poorly known, radiation breeding has produced thousands of useful mutants and a sizable fraction of the world’s crops...including varieties of rice, wheat, barley, pears, peas, cotton, peppermint, sunflowers, peanuts, grapefruit, sesame, bananas, cassava and sorghum." Mutagenic varieties tend to be made freely available for plant breeding, in contrast to many commercial plant varieties or germplasm that increasingly have restrictions on their use such as terms of use, patents and proposed Genetic user restriction technologies and other intellectual property
Intellectual property
Intellectual property is a term referring to a number of distinct types of creations of the mind for which a set of exclusive rights are recognized—and the corresponding fields of law...
regimes and modes of enforcement.
Mutagenic varietals
- Osa Gold PearPearThe pear is any of several tree species of genus Pyrus and also the name of the pomaceous fruit of these trees. Several species of pear are valued by humans for their edible fruit, but the fruit of other species is small, hard, and astringent....
- Rio Star GrapefruitGrapefruitThe grapefruit , is a subtropical citrus tree known for its sour fruit, an 18th-century hybrid first bred in Barbados. When found, it was named the "forbidden fruit"; it has also been misidentified with the pomelo or shaddock , one of the parents of this hybrid, the other being sweet orange The...
- Todd’s Mitcham PeppermintPeppermintPeppermint is a hybrid mint, a cross between the watermint and spearmint . The plant, indigenous to Europe, is now widespread in cultivation throughout all regions of the world...
(Verticillium wilt toleranceVerticillium wiltVerticillium Wilt is a wilt disease of over 300 species of eudicot plants caused by one of two species of Verticillium fungus, V. dahliae and V. albo-atrum. Many economically important plants are susceptible including cotton, tomatoes, potatoes, eggplants, peppers and ornamentals, as well as others...
) - Murray Mitcham PeppermintPeppermintPeppermint is a hybrid mint, a cross between the watermint and spearmint . The plant, indigenous to Europe, is now widespread in cultivation throughout all regions of the world...
(Verticillium wilt toleranceVerticillium wiltVerticillium Wilt is a wilt disease of over 300 species of eudicot plants caused by one of two species of Verticillium fungus, V. dahliae and V. albo-atrum. Many economically important plants are susceptible including cotton, tomatoes, potatoes, eggplants, peppers and ornamentals, as well as others...
) - Calrose 76 RiceRiceRice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
(short height rice induced with gamma rays)
- Purple Orchard 3 Sweet potatoSweet potatoThe sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...
- PNR-381 RiceRiceRice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
- Sharbati Sonora wheatWheatWheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
- ‘MUM 2’, ‘BM 4’, ‘LGG 407’, ‘LGG 450’,
‘Co4’, ‘Dhauli’ (TT9E), ‘Pant moong-1’ blackgram (YMC], [(Yellow mosaic virus) resistance)
Release by nation
As of 2004 the percentage of all mutagenic varietals released globally, by country, were :- (26.8%)
- (11.5%)
- (9.3%) +
- (7.8%)
- (5.7%)
- (5.3%)