Hybrid rice uses what we call traditional breeding methods. The general breeding idea is to choose a variety A with good traits in all aspects and poor traits in some aspects, and then choose a variety B with one or several good traits, so that the traits of the two varieties are just complementary. Then, through hybridization, the genes controlling excellent traits of variety B were transferred to variety A, so as to obtain offspring with excellent traits. Because this method can't guarantee that you can get the ideal offspring every time you cross, you need to cross many times and a lot. It takes about ten years for a new variety, such as 108 corn from China Agricultural University, and it took twenty years to breed.
Why is it controversial? The general public's anxiety about genetic modification is basically bewitched by the fundamentalism of some people who oppose genetic modification, and they don't understand why there are problems. Science suspects that some ecologists think that ecological diversity is a better way to increase production, and some people worry that gene drift caused by pollen transmission will lead to the vigorous growth of weeds, but absolutely no scientist thinks that eating genetically modified products will transform people's genes (this is too unreliable. . . ) With regard to the inquiry, I naturally strongly recommend reading this article:/news/2008/081015/full/455850a.html. In addition, there are some arguments about economic interests, because I am not a professional in this field, so I don't understand them. Some people are discussing the issue of patent, because my knowledge of patent law is superficial, and I know that it is not impossible for professionals to talk about it, so I also avoid this issue.
Hybrid rice is a crop that has been proved by practice, and not only Yuan Longping has done well, but also Academician Chen of Shenyang Agricultural University has done well. I don't know if I exaggerated Yuan Longping, but after all, the results were made by the team he led, and the effect was good. Personally, I don't care if anyone exaggerates.
Finally, I think traditional farming cannot be abandoned. It is very important to obtain a batch of germplasm resources belonging to us through traditional breeding, which will also produce some unexpected results. However, it is the general trend to adopt molecular breeding methods such as genetic engineering, which are being carried out all over the world. If China people fall behind in this respect, it will be a great blow. Transgenic cotton is a positive example, while transgenic soybean is a living negative textbook.
Organic food refers to the agricultural and sideline products that come from the organic agricultural production system, are produced and processed in accordance with international organic agricultural production requirements and corresponding standards, and are certified by independent organic food certification bodies, including grain, vegetables, fruits, dairy products, livestock products, honey, aquatic products and condiments. Organic food needs to meet the following conditions: raw materials must come from established organic agricultural production systems or organically collected wild natural products; Products in the whole production process strictly follow the processing, packaging, storage and transportation standards of organic food; In the process of organic food production and circulation, producers have a sound quality control and follow-up review system, and complete production and sales records and files; Must be certified by an independent organic food certification body. Therefore, organic food is a kind of environment-friendly and safe food that really comes from nature, with rich nutrition and excellent quality.
Genetically modified food refers to food, food raw materials and food additives made or produced by animals, plants and microorganisms improved by biotechnology. According to one or some characteristics, by some biotechnology methods, the genes of animals and plants are modified to make animals, plants or microorganisms have or enhance secondary characteristics, which can reduce production costs and improve the value of food or food raw materials. At present, scientists all over the world can't draw a conclusion about the safety of genetically modified food in a short time. Although controversial, one thing to remind everyone is that all kinds of genetically modified foods must be indicated in the trademark, so their safety is worrying.
There are three main differences between organic food and other foods:
(1) It is absolutely forbidden to use synthetic substances such as pesticides, fertilizers and hormones in the production and processing of organic food.
(2) Genetic engineering technology is not allowed in organic food;
(3) Other foods are allowed to use these substances in a limited way, and the use of genetic engineering technology is not prohibited.
This understanding is not accurate. Hybridization is a process of rearrangement and screening, while transgene is a process of introducing new expression factors and re-creating.
If we use hybridization technology, that is to say, we choose the high one for affinity, and the offspring may be high or short, and we only leave the high one for affinity. Through this artificial screening, after several generations, most of the highly expressed groups were obtained. This species is still this species, and the genetic composition has not changed.
If it is transgenic technology, that is to say, a species originally has no wings, winged genes are introduced into this species through transgenic technology and expressed. In fact, this species has become a new species, which is obviously different from the previous mother.
Give a relationship to explain: a species' genes have two expression forms of AB, then the offspring genes of this species can only be the combination form of three genes of AA AB BB.
If it is transgenic, the species may express new combinations, such as AC AE AF, BC BE BF, etc. New genes introduced according to transgenic technology.