History
 | This section needs expansion. You can help by adding to it. (October 2014) |
In the US, experimental agriculture stations in the 1920s investigated the hybrid crops, and by the 1930s farmers had widely adopted the first hybrid maize. [5]
In agriculture and gardening, hybrid seed is produced by deliberately cross-pollinating parent plants which are genetically distinct. The parents are usually two inbred strains.
Hybrid seed is common in industrial agriculture and home gardening. It is one of the main contributors to the dramatic rise in agricultural output during the last half of the 20th century. [1] Alternatives to hybridization include open pollination and clonal propagation. [2]
An important factor is the heterosis that results from the genetic differences between the parents, which can produce higher yield and faster growth rate. Crossing any particular pair of inbred strains may or may not result in superior offspring. The parent strains used are carefully chosen so as to achieve the uniformity that comes from the uniformity of the parents, and the superior performance that comes from heterosis. [3]
Elite inbred strains are used that express well-documented and consistent phenotypes with yield that is relatively good for inbred plants. [2] Other characteristics of the parents are carefully chosen to provide desirable traits such as improved color, flavour, or disease resistance.
Hybrid seeds planted by the farmer produce similar plants, but the seeds of the next generation from those hybrids will not consistently have the desired characteristics because of genetic assortment. It is therefore rarely desirable to save the seeds from hybrid plants to start the next crop. [4]
| | This section needs expansion. You can help by adding to it. (October 2014) |
In the US, experimental agriculture stations in the 1920s investigated the hybrid crops, and by the 1930s farmers had widely adopted the first hybrid maize. [5]
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera. Hybrids are not always intermediates between their parents such as in blending inheritance, but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are.
Triticale is a hybrid of wheat (Triticum) and rye (Secale) first bred in laboratories during the late 19th century in Scotland and Germany. Commercially available triticale is almost always a second-generation hybrid, i.e., a cross between two kinds of primary (first-cross) triticales. As a rule, triticale combines the yield potential and grain quality of wheat with the disease and environmental tolerance of rye. Only recently has it been developed into a commercially viable crop. Depending on the cultivar, triticale can more or less resemble either of its parents. It is grown mostly for forage or fodder, although some triticale-based foods can be purchased at health food stores and can be found in some breakfast cereals.
Selective breeding is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals.
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of its parents. The heterotic offspring often has traits that are more than the simple addition of the parents' traits, and can be explained by Mendelian or non-Mendelian inheritance. Typical heterotic/hybrid traits of interest in agriculture are higher yield, quicker maturity, stability, drought tolerance etc.
Yuan Longping was a Chinese agronomist and inventor. He was a member of the Chinese Academy of Engineering known for developing the first hybrid rice varieties in the 1970s, part of the Green Revolution in agriculture. For his contributions, Yuan is known as the "Father of Hybrid Rice". Yuan was bestowed the Medal of the Republic, the highest honorary medal of the People's Republic of China, in September 2019.
F1 hybrid (also known as filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where the term F1 crossbreed may be used. The term is sometimes written with a subscript, as F1 hybrid. Subsequent generations are called F2, F3, etc.
In agriculture and gardening, seed saving is the practice of saving seeds or other reproductive material from vegetables, grain, herbs, and flowers for use from year to year for annuals and nuts, tree fruits, and berries for perennials and trees. This is the traditional way farms and gardens were maintained for the last 12,000 years.
"Open pollination" and "open pollinated" refer to a variety of concepts in the context of the sexual reproduction of plants. Generally speaking, the term refers to plants pollinated naturally by birds, insects, wind, or human hands.
Seed companies produce and sell seeds for flowers, fruits and vegetables to commercial growers and amateur gardeners. The production of seed is a multibillion-dollar global business, which uses growing facilities and growing locations worldwide. While most of the seed is produced by large specialist growers, large amounts are also produced by small growers who produce only one to a few crop types. The larger companies supply seed both to commercial resellers and wholesalers. The resellers and wholesalers sell to vegetable and fruit growers, and to companies who package seed into packets and sell them on to the amateur gardener.
Detasseling corn is removing the pollen-producing flowers, the tassel, from the tops of corn (maize) plants and placing them on the ground. It is a form of pollination control, employed to cross-breed, or hybridize, two varieties of corn.
An heirloom plant, heirloom variety, heritage fruit, or heirloom vegetable is an old cultivar of a plant used for food that is grown and maintained by gardeners and farmers, particularly in isolated communities of the Western world. These were commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture.
Plant breeders use different methods depending on the mode of reproduction of crops, which include:
Hybrid rice is a type of Asian rice that has been crossbred from two very different parent varieties. As with other types of hybrids, hybrid rice typically displays heterosis or "hybrid vigor", so when grown under the same conditions as comparable purebred rice varieties, it can produce up to 30% more yield. To produce hybrid seeds in large quantity, a purebred sterile rice variety is fertilized with fertile pollen from a different variety. High-yield crops, including hybrid rice, are one of the most important tools for combatting worldwide food crises.
The Connecticut Agricultural Experiment Station (CAES) is the Connecticut state government's agricultural experiment station, a state government component that engages in scientific research and public outreach in agriculture and related fields. It is the oldest state experiment station in the United States, having been founded in 1875. Its official mission is to "develop, advance, and disseminate scientific knowledge, improve agricultural productivity and environmental quality, protect plants, and enhance human health and well-being through research for the benefit of Connecticut residents and the nation." The station operates a main research campus in New Haven, a research farm in Hamden, a satellite research facility and farm in Windsor, and a research farm in Griswold. The Storrs Agricultural Experiment Station is a separate agricultural research agency, founded in 1887 and part of the University of Connecticut, which also receives state and federal funding.
Plant genetics is the study of genes, genetic variation, and heredity specifically in plants. It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems. Plant genetics is similar in many ways to animal genetics but differs in a few key areas.
F. Wolfgang Schnell was a German professor of applied genetics and plant breeding. He belonged to the most prominent scientists in his field during the second half of the 20th century.
Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. The goals of plant breeding are to produce crop varieties that boast unique and superior traits for a variety of applications. The most frequently addressed agricultural traits are those related to biotic and abiotic stress tolerance, grain or biomass yield, end-use quality characteristics such as taste or the concentrations of specific biological molecules and ease of processing.
Plant breeding started with sedentary agriculture, particularly the domestication of the first agricultural plants, a practice which is estimated to date back 9,000 to 11,000 years. Initially, early human farmers selected food plants with particular desirable characteristics and used these as a seed source for subsequent generations, resulting in an accumulation of characteristics over time. In time however, experiments began with deliberate hybridization, the science and understanding of which was greatly enhanced by the work of Gregor Mendel. Mendel's work ultimately led to the new science of genetics. Modern plant breeding is applied genetics, but its scientific basis is broader, covering molecular biology, cytology, systematics, physiology, pathology, entomology, chemistry, and statistics (biometrics). It has also developed its own technology. Plant breeding efforts are divided into a number of different historical landmarks.
Dilbagh Singh Athwal was an Indian-American geneticist, plant breeder and agriculturist, known to have conducted pioneering research in plant breeding. He was a professor and the Head of the Department of Plant Breeding at Punjab Agricultural University and an associate of Norman Borlaug, a renowned biologist and Nobel Laureate, with whom he has collaborated for the introduction of high-yielding dwarf varieties of wheat.
Dhara Mustard Hybrid-11, otherwise known as DMH - 11, is a genetically modified hybrid variety of the mustard species Brassica juncea. It was developed by Professor Deepak Pental from the University of Delhi, with the aim of reducing India's demand for edible oil imports. DMH - 11 was created through transgenic technology, primarily involving the Bar, Barnase and Barstar gene system. The Barnase gene confers male sterility, while the Barstar gene restores DMH - 11's ability to produce fertile seeds. The insertion of the third gene Bar, enables DMH - 11 to produce phosphinothricin-N- acetyl-transferase, the enzyme responsible for Glufosinate resistance. This hybrid mustard variety has come under intense public scrutiny, mainly due to concerns regarding DMH - 11's potential to adversely affect the environment as well as consumer health. DMH - 11 was found not to pose any food allergy risks, and has demonstrated increased yields over existing mustard varieties. Conflicting details and results regarding the field trials and safety evaluations conducted on DMH - 11 have delayed its approval for commercial cropping.
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