Favorable aspect
1. In the past, the variety of plants was mainly changed by breeding. This traditional breeding method takes a long time, the hybrid varieties are not easy to control and the purpose is poor. Their offspring may have high yield but no disease resistance, or they may have high yield but poor quality, so they must be bred repeatedly. Transgenic technology is different. You can select any 1 target gene and get 1 corresponding new variety. You are worth looking forward to.
Screening takes so long.
2. Traditional breeding can only be rice to rice, corn to corn, not rice to corn and rice to bacteria. Transgenic technology can not only combine the genes of different plants, but also combine the genes of animals and even humans into plants. For example, scientists took a fancy to the gene of a polar bear and thought it had anti-freezing effect, so they separated it out and implanted it into tomatoes to cultivate cold-resistant tomatoes.
● Through transgenic technology, new crop varieties with high yield, high quality, antiviral, insect-resistant, cold-resistant, drought-resistant, waterlogging-resistant, salt-tolerant and herbicide-resistant can be cultivated, thus reducing dependence on pesticides, fertilizers and water, reducing agricultural costs, greatly increasing yield per unit area, improving food quality and alleviating the contradiction of world food shortage. For example, after planting cecropin gene, the ability of potato to resist bacterial wilt and soft rot is greatly improved. In the past, these two diseases reduced production by nearly 30% every year. A potato resistant to Colorado potato beetle can save 370 thousand kilograms of pesticides every year in the United States; After sowing transgenic soybean seeds in Argentina, the ability of soybean to resist diseases and weeds was greatly improved, the dosage of pesticides and herbicides was reduced, and the production cost was reduced by 15%.
● Using transgenic technology to produce healthy and disease-resistant foods. Dupont and Monsanto are about to launch a variety of soybeans that can extract heart-healthy edible oil. The two companies will also jointly launch new varieties of fortified soybeans, which taste better and are easier to digest. Ailm, in cooperation with other companies, is studying tomatoes with high content of anticancer substances and corn and soybeans that can be used to produce hemoglobin. In addition, bananas and potatoes containing vaccines are also under intensive research; Japanese scientists have successfully cultivated new rice varieties that can reduce serum cholesterol content and prevent arteriosclerosis through transgenic technology; European scientists have newly bred transgenic rice rich in vitamin A and iron, which may help reduce the incidence of iron deficiency anemia and vitamin A deficiency around the world, especially in developing countries where rice is the staple food.
● Genetically modified foods can get rid of the influence of seasons and climate, so that people can eat fresh fruits and vegetables all year round. At the same time, people also found that the fruits produced by genetically modified crops have unique flavor both in appearance and taste. British scientists transplanted a gene that can destroy chlorophyll variation into grass, which can make the grass evergreen all the year round. In addition to the greening function, it is also good for animal husbandry. Because grass is more nutritious than hay, it improves meat quality.
6. Using transgenic technology, exogenous genes such as auxin gene, prolificacy gene, egg stimulating hormone gene, high lactation gene, lean meat gene, keratin gene, anti-parasite gene and antiviral gene are introduced into animal sperm, egg cells or fertilized eggs, so that animals with short growth cycle, many litters, high lactation, good meat quality and processing performance and disease resistance can be cultivated.
shortcomings
The application of any new technology has two sides. The development and utilization of nuclear energy not only provides mankind with huge nuclear energy, but also creates nuclear weapons that are extremely destructive to mankind; The application of pesticides has played a great role in the prevention and control of crop pests, which has greatly increased the output of crops, but it has also caused great harm to people, livestock and the environment. The industrial revolution has not only brought great wealth to human society, but also brought disastrous environmental pollution and the destruction of ecological balance.
Genetically modified foods also have two sides.
1. It is reported that scientists have found that some genetically modified products may contain toxic substances and allergens, which will have adverse effects on human health and even cause cancer or some genetic diseases. Although there is no convincing research report that these improved varieties are toxic, some researchers believe that artificial extraction and addition of genes may achieve some ideal results, but it will also increase and accumulate trace toxins in food. The accumulation of this toxin is a long process, but it may indeed be in progress, so no one can be sure that these improved varieties are not toxic at present. A research report by Professor Pusta, a British scientist, said that genetically modified potatoes would do harm to the liver, stomach and immune system of experimental mice. Although his experimental results need to be further confirmed, it can still remind people that genetically modified foods may be harmful to human health. Secondly, allergic reaction. People who are allergic to 1 food are sometimes allergic to 1 food that was not allergic before, because this kind of food contains protein that causes allergies. For example, scientists have added a certain gene of corn to the genes of walnuts, wheat and shellfish, so people who were allergic to corn before may be allergic to walnuts, wheat and shellfish.
Some researchers believe that foreign genes will destroy the nutrients in food in ways that people don't know yet. According to the experimental report of the American Center for Ethics and Toxicity, compared with ordinary soybeans, the anti-cancer component isoflavones in herbicide-resistant transgenic soybeans are reduced.
3. A large number of genetically modified organisms are likely to cross with wild species after entering nature, resulting in genetic pollution, thus affecting the protection and sustainable utilization of biodiversity. This kind of pollution is more harmful to the environment and ecosystem than any other factor. For example, herbicide-resistant transgenic rape can infect wild mustard, thus making wild mustard insensitive to weed control measures.
4. Some crops with insect-resistant or antifungal genes may play a role in other non-target organisms, thus killing beneficial insects and fungi in the environment. Some scientists have done such a set of control experiments in the laboratory, feeding insect-resistant transgenic corn to corn borer and Chrysopa respectively. The experimental results show that the maturity of Chrysopa is 3 days later than normal when the mortality rate of stem borers is as high as 60%. Chrysopa is a beneficial insect, which is widely propagated by farmers and used to control agricultural pests such as cotton bollworm and aphid. This experiment proves that insect-resistant transgenic corn has no ability to identify beneficial insects and pests. It poisons pests and harms beneficial insects. Planting insect-resistant crops on a large scale may mean reducing the population of beneficial insects. 1999 In May, the British magazine Nature published a paper by john rossi, an associate professor at Cornell University in the United States, which attracted worldwide attention. The article said that the pollen of insect-resistant transgenic "BT corn" contains toxins, and butterfly larvae will develop poorly after eating leaves sprinkled with this pollen, and the mortality rate is particularly high. Scientists believe that the implantation of BT gene can make corn produce substances that kill pests, thus having the ability to resist pests, but it is also toxic and may have adverse effects on the ecological environment. At present, more than 100 laboratories in China are conducting biotechnology research, and some genetically modified crops have been approved for commercialization and large-scale planting. Although the only domestic genetically modified foods that can really be eaten by ordinary people are sweet peppers (a kind of persimmon peppers) and tomatoes with delayed ripening, many imported foods may contain genetically modified ingredients. The status quo that can't be ignored is that when the foreign anti-GM food movement is in full swing and the safety issues are already surging, most domestic consumers have not yet figured out what "GM" is. Therefore, we should step up publicity to let Chinese people know about genetically modified foods and establish China's biosafety law as soon as possible. In the future, both China people and foreigners will develop, produce and sell genetically modified foods in China legally, scientifically and orderly, so as to avoid the evil consequences of "development first, management later" in the United States and Canada. Foreign companies are prohibited from conducting dangerous experiments and selling genetically modified foods that have not passed the safety inspection in China. Otherwise, you may not see its benefits, suffer first, or even lose more than you gain. China's Consumer Protection Law also clearly stipulates that consumers should enjoy the right to know about commodities. At present, labeling of genetically modified foods is widely used abroad, but there is no requirement for labeling of genetically modified foods in China, which is not in line with the principle of consumers knowing. Let consumers fully understand and understand genetically modified food, which not only protects the legitimate rights and interests of consumers, but also contributes to the healthy development of genetically modified food.