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How GM plants are produced?
What does GM mean in biology?
What is genetic modification (GM)?
How does GM work?
What are the characteristics of GM crops?
What are genetic modified organisms (GMOs)?
What is genetic modification (GM) of crops and how is it done? GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells. Usually, the cells are then grown in tissue culture where they develop into plants. The seeds produced by these plants will inherit the new DNA.
- How does GM differ from conventional plant breeding?
How does GM differ from conventional plant breeding? The...
- How does GM differ from conventional plant breeding?
Genetically modified crops (GM crops) are plants used in agriculture, the DNA of which has been modified using genetic engineering methods. Plant genomes can be engineered by physical methods or by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors.
How does GM differ from conventional plant breeding? The goal of both GM and conventional plant breeding is to produce crops with improved characteristics by changing their genetic makeup. GM achieves this by adding a new gene or genes to the genome of a crop plant.
- Overview
- GMOs in agriculture
A genetically modified organism (GMO) is an organism whose DNA has been modified in the laboratory in order to favour the expression of desired physiological traits or the production of desired biological products.
Why are genetically modified organisms important?
Genetically modified organisms (GMOs) provide certain advantages to producers and consumers. Modified plants, for example, can at least initially help protect crops by providing resistance to a specific disease or insect, ensuring greater food production. GMOs are also important sources of medicine.
Are genetically modified organisms safe for the environment?
Assessing the environmental safety of genetically modified organisms (GMOs) is challenging. While modified crops that are resistant to herbicides can reduce mechanical tillage and hence soil erosion, engineered genes from GMOs can potentially enter into wild populations, genetically modified crops may encourage increased use of agricultural chemicals, and there are concerns that GMOs may cause inadvertent losses in biodiversity.
Should genetically modified crops be grown?
Genetically modified (GM) foods were first approved for human consumption in the United States in 1994, and by 2014–15 about 90 percent of the corn, cotton, and soybeans planted in the United States were GM. By the end of 2014, GM crops covered nearly 1.8 million square kilometres (695,000 square miles) of land in more than two dozen countries worldwide. The majority of GM crops were grown in the Americas.
Engineered crops can dramatically increase per area crop yields and, in some cases, reduce the use of chemical insecticides. For example, the application of wide-spectrum insecticides declined in many areas growing plants, such as potatoes, cotton, and corn, that were endowed with a gene from the bacterium Bacillus thuringiensis, which produces a natural insecticide called Bt toxin. Field studies conducted in India in which Bt cotton was compared with non-Bt cotton demonstrated a 30–80 percent increase in yield from the GM crop. This increase was attributed to marked improvement in the GM plants’ ability to overcome bollworm infestation, which was otherwise common. Studies of Bt cotton production in Arizona, U.S., demonstrated only small gains in yield—about 5 percent—with an estimated cost reduction of $25–$65 (USD) per acre owing to decreased pesticide applications. In China, where farmers first gained access to Bt cotton in 1997, the GM crop was initially successful. Farmers who had planted Bt cotton reduced their pesticide use by 50–80 percent and increased their earnings by as much as 36 percent. By 2004, however, farmers who had been growing Bt cotton for several years found that the benefits of the crop eroded as populations of secondary insect pests, such as mirids, increased. Farmers once again were forced to spray broad-spectrum pesticides throughout the growing season, such that the average revenue for Bt growers was 8 percent lower than that of farmers who grew conventional cotton. Meanwhile, Bt resistance had also evolved in field populations of major cotton pests, including both the cotton bollworm (Helicoverpa armigera) and the pink bollworm (Pectinophora gossypiella).
Other GM plants were engineered for resistance to a specific chemical herbicide, rather than resistance to a natural predator or pest. Herbicide-resistant crops (HRC) have been available since the mid-1980s; these crops enable effective chemical control of weeds, since only the HRC plants can survive in fields treated with the corresponding herbicide. Many HRCs are resistant to glyphosate (Roundup), enabling liberal application of the chemical, which is highly effective against weeds. Such crops have been especially valuable for no-till farming, which helps prevent soil erosion. However, because HRCs encourage increased application of chemicals to the soil, rather than decreased application, they remain controversial with regard to their environmental impact. In addition, in order to reduce the risk of selecting for herbicide-resistant weeds, farmers must use multiple diverse weed-management strategies.
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Another example of a GM crop is golden rice, which originally was intended for Asia and was genetically modified to produce almost 20 times the beta-carotene of previous varieties. Golden rice was created by modifying the rice genome to include a gene from the daffodil Narcissus pseudonarcissus that produces an enzyme known as phyotene synthase and a gene from the bacterium Erwinia uredovora that produces an enzyme called phyotene desaturase. The introduction of these genes enabled beta-carotene, which is converted to vitamin A in the human liver, to accumulate in the rice endosperm—the edible part of the rice plant—thereby increasing the amount of beta-carotene available for vitamin A synthesis in the body. In 2004 the same researchers who developed the original golden rice plant improved upon the model, generating golden rice 2, which showed a 23-fold increase in carotenoid production.
The genetic material is modified artificially to give it a new property (e.g. a plant's resistance to a disease, insect or drought, a plant's tolerance to a herbicide, improving a food's quality or nutritional value, increased yield). Such organisms are called "genetically modified organisms" (GMOs).
Sep 21, 2005 · Genetic modification (GM) is the heritable alteration of the genetic make-up of an organism. As a natural process, genetic modification (GM) is as old as genes themselves, and has been utilised by human beings since the beginnings of agriculture.
What is genetic modification (GM)? GM is the alteration of genetic material (DNA) in a way that would not occur outside the laboratory. GM includes a range of techniques that allow specific DNA to be moved with a high level of precision,
