There are a wide range of genetically modified traits that farmers use to boost crop productivity and quality. Some, like herbicide tolerance and insect resistance, are designed to protect crops from harmful chemicals and pests.
Other GM traits stretch the genetic potential of plants, for example by enhancing protein and oil content. Others are designed to lower the amount of water and nutrients required for a given crop.
History
Genetically modified (GM) seeds are the fruits of a long-term research and development effort. It started in the 1940s when scientists and breeders began seeking new means to introduce variation into the gene pool. Eventually, they developed genetic engineering as a more precise and controllable method to create plants with desirable traits.
GM crops are genetically engineered to produce a specific trait, such as insect resistance or herbicide tolerance. In some cases, a plant’s entire genome is altered to include the desired trait. This can occur through recombination, in which the DNA of another organism is combined with the DNA of another species to form a new genetic lineage.
For example, a gene from the soil bacterium Bacillus thuringiensis is added to a corn plant and gives it insect resistance. Then, the crop is grown in the laboratory and monitored for a year to make sure that it is not changing the other characteristics of the plant.
If the test is successful, the resulting corn plant is then marketed and sold to farmers. It must go through extensive health and environmental testing to be approved by the United States Department of Agriculture.
Some critics say that GM crops can cause serious problems. They argue that if pests and weeds evolve a tolerance to chemicals engineered into GM crops, they can kill them, or become immune to a herbicide sprayed on nearby fields of the same variety.
Critics also worry that the use of GM seeds will result in vast monocultures. They assert that if the same pests and weeds develop tolerance to the GM plants, then monocultures will be unable to protect themselves from a range of attacks, including drought and disease or locust swarms.
But supporters of GM crops argue that these seeds are thoroughly tested and highly regulated. They believe they can reduce the cost of farming by allowing farmers to use fewer chemical inputs, and that they will boost yields and profits by increasing crop production.
Origins
The origins of genetically modified seeds date back thousands of years. Early farmers used techniques like selective breeding and cross-breeding to breed plants with desirable traits. Today’s genetically engineered crops, including corn, cotton, soybeans, and canola, were developed through the use of modern biotechnology techniques like gene splicing and genetic engineering.
To create a GMO plant, scientists first identify the desired trait, then find an organism with that trait in its genes. For example, if they wanted to produce insect-resistant corn, they would use bacteria that produce a natural insecticide.
Once they have found the bacterium with the gene for the desired trait, they then copy that DNA in the corn seed. They do this by creating a plasmid. Plasmids are small pieces of DNA that can fit through the walls of a plant cell and into the nucleus of the plant itself.
By using this method, they can control the location of the gene and ensure that it is inherited in a predictable way. After the plasmid is produced, the plant developers do a series of trials to test whether the new gene works.
Those tests are done in greenhouses and growth chambers before the final product is planted on fields. Once they are satisfied with the results, they submit their new plants to national competent authorities for regulatory approval.
The evolution of genetically modified seeds has changed the face of agriculture and has opened up new opportunities for food producers. Crops can now be created that are drought-tolerant, resistant to pesticides, or have other characteristics that weren’t possible before.
Some people have concerns about the safety of GMOs. They worry that genetically modified plants might contaminate non-GMO crops and thereby reduce the ability of farmers to produce their own food.
They also fear that the plants might be contaminated with pesticides or herbicides. These fears have prompted many anti-biotech activists to sue farmers who use patented GMOs.
Despite the concerns about the safety of GMOs, they are growing rapidly worldwide. This growth is driven by the desire for higher yields and improved quality of products.
Development
Genetically modified seeds have been developed by numerous companies. The most important of those developments are the introduction of herbicide tolerant (HT) and insect resistant (IR) varieties, which allow farmers to reduce their use of pesticides and increase their productivity.
HT plants are engineered to produce an enzyme that metabolizes the herbicide glyphosate, thereby reducing the need for farmers to apply a range of different weed-killing chemicals. They also enable growers to control a variety of broad-leaf and grass weeds without damaging conventional crops. They have been adopted by farmers in most developing countries because they help them improve crop yields, reduce pest damage and minimize the need for additional chemicals.
A number of studies have been conducted on the environmental impact of GM seeds. In general, these studies found that HT and IR varieties reduced the use of pesticides and triggered reductions in greenhouse gas emissions associated with their cultivation. In addition, HT seeds also allowed for the transition from traditional plantation systems to direct planting, with far less soil preparation and mechanized ploughing.
The IR trait in cotton, which uses Bacillus thuringiensis, a soil bacterium, to kill certain insects, is also considered environmentally friendly because it reduces the need for chemical insecticides. Several studies have been conducted in both industrialized and developing countries to evaluate the impacts of IR technologies, and results show that they lead to an estimated 20% reduction of the environmental impact of irrigated cotton production.
This is achieved through the reduction in insecticides and weed control applications, as well as by using less fuel for machinery and aerial spraying. In addition, IR crops also help producers transition from the practice of using multiple spraying technologies to just one single application system.
In Brazil, a major shift in the use of GM soybeans occurred around 2013 when Monsanto launched Soja Intacta ™, which expresses both HT and IR traits. This stacked cultivar quickly replaced the majority of traditional soybean varieties that expressed only HT tolerance to glyphosate, and it became the dominant GM crop in Brazilian soy.
Impact
There are many different kinds of genetic modifications that can be made to a crop, including pesticide resistance, disease resistance and drought tolerance. These types of changes can be beneficial to farmers, but they can also be harmful to the environment.
GM crops may be detrimental to the environment when they are over sprayed with pesticides like Roundup. These chemicals can damage the soil, kill insects and cause the weeds to become resistant to these same pesticides. The result is a’super weed’ that can grow in places where a normal weed would not.
Another concern is the potential for unauthorized release of GMOs into the environment. This can be caused by traces of GM seeds settling in the ground when the crops are planted or through accidental spillage and/or contamination at processing plants.
These concerns can be addressed through careful seed selection and planting, which limits the possibility of unauthorized releases into the soil. In addition, seed processing facilities should be checked to ensure that they are not contaminated with GM seeds.
Despite these risks, the use of GM crops has had a positive impact on the world’s food supply and consumption. It can mitigate food shortages due to climate change and other factors, increase farmers’ incomes and improve the nutritional quality of foods.
Some GM crops have been studied for their ability to reduce the occurrence of food allergies. For example, GM soybeans that are tolerant to the protein from Brazil nuts can make the food less likely to trigger allergies in people who normally react negatively to these seeds.
Other studies have found that GM crops have been effective in improving nutrition by increasing the amount of protein and vitamins. These improvements can help people with certain health conditions, such as obesity and diabetes.
In addition, GM crops can provide seeds that are resistant to climate change. This can be particularly important in developing countries, where climate change is expected to have a negative impact on agricultural production and consumption.
