What are the main influential factors and how to produce them are still inconclusive. After the seeds of crops traveling in space are planted on the ground, not only the plants are obviously increased and thickened, but also the fruit types are increased, the yield is generally improved and the quality is greatly improved. The influence of space environment on plant genes has been confirmed by scientists all over the world. However, the explanation of the principle of space breeding is still controversial.
Edit this paragraph What is space breeding?
Space breeding: Also known as space mutation breeding, it is to send crop seeds or test-tube seedlings into space, make use of the mutation effect of special space environment (high vacuum, cosmic high-energy ion radiation, cosmic magnetic field and high cleanliness) that cannot be simulated on the ground, make the seeds mutate, and then return to the ground to select new seeds, new materials and cultivate new crop breeding technology. Space breeding includes space breeding.
Beneficial varieties, large increase, fast stable yield, high yield, high quality, early maturity and strong disease resistance. The mutation rate is 3-4 times higher than that of ordinary mutation breeding, and the breeding cycle is shortened by about 1 times, from about 8 years to about 4 years. At present, only the United States, the Russian Federation and China have successfully carried out space-borne breeding. China began to carry vegetables into the sky in 1987. Space breeding is a new way of agricultural breeding integrating space technology, biotechnology and agricultural breeding technology. It is one of the most advanced scientific and technological topics in the field of agriculture in the world today. Through the experiments of space agriculture, many mysteries of plants, animals and other biological characteristics have been revealed. At present, only the United States, the Russian Federation and China have recoverable satellite technology. In this respect, China is at the forefront of the world.
Edit the outline of this paragraph.
In June, 2002, the Space Laboratory of the University of Wisconsin in the United States began to carry out space mutation. The purpose of taking roses to heaven is to obtain rose mutants with high oil content in roses; At the same time, there are soybeans, mainly to obtain excellent soybean characters. Russia used to take green or white poles (Picea of Pinaceae, Abies subfamily) into the sky as Christmas trees. Now they are widely planted in Siberia and Kazakhstan, and the Christmas trees coming back from space grow very tall. The United States once gave up space mutation and is now stepping up its research. The study of plant growth, development and genetic variation by using space environment began in the 1960s. China's space breeding began in 1987. At first, we just wanted to know what would happen when the seeds were taken into space. Since 1 August 5, 1987, when the recoverable satellite carried plant seeds1time, China has successfully conducted1time space breeding experiments. The seeds of more than 70 kinds of plants with 1000 varieties were tested in space breeding, which attracted more than 70 units from 23 provinces (cities) to participate in the seed carrying test. Through space breeding, a new rice line with big panicle, big grain, high quality and high yield has emerged. For example, the new rice variety Yuhang 1 bred by space mutation breeding, the plant height decreased 14 em, the growth period shortened 13 d, and the yield increased by 5% ~ 10%. Huahang 1, a new rice variety, has large panicle and many grains, and high seed setting rate, which can increase the yield by 10% to 7 500 kg/hm2. In addition, many new wheat lines with short stature, high yield and early maturity were obtained through space breeding, and their yield was higher than that of ordinary varieties 10% ~ 15%. In green pepper breeding, L batches of new strains with high yield, high quality and disease resistance have been cultivated through space breeding, such as green pepper with a single fruit weight of 8-2. 250g, the yield was 75 1300kg/hm2, and the content of vitamin C increased by 20%. According to incomplete statistics, so far, 22 provinces (cities) have participated in space breeding, 38 varieties have passed the national examination and approval, and more than 80 varieties have been widely promoted. In the past, space breeding was mainly based on rice, wheat and vegetables, but now it has been extended to timber trees in forestry, garden plants in urban forest landscape and oil plants called energy plants today, some of which have been widely promoted, especially in Guangxi, Fujian and Gansu. 1994 and 1996, the maize research institute of Sichuan Agricultural University took the lead in the research of maize space mutation breeding in China, from which 1 new materials with dwarf effect and controlled by recessive single gene were obtained, which provided valuable resources for genetic research and breeding utilization. This sterile material has undeveloped tassels, few branches, signs of degeneration at the top of branches, and no anthers exposed in sterile plants. Sterile anthers are thin and small, only 1/3 of fertile anthers. Sterile anthers are crushed, no pollen is scattered, abortion is complete, fertility is stable, and it is not affected by environmental conditions such as light and temperature. It is 1 "pollen-free" male sterility. The main reason for the change of biological characters in space environment is that space environment factors cause chromosome damage, which leads to the repair of damaged parts by organisms, which leads to a large number of repair errors in the process of repair, changes the DNA structure of chromosomes and causes the variation of expression characters.
Edit this study area
As early as the 1980s, the forest genetics and breeding community received an inquiry from the space department whether any forest seeds were sent to the sky. Because the test period is long and the quantitative nature of radiation is difficult to change, this matter has not been answered. Now experts are paying more and more attention to forest seeds. For various reasons, two changes have taken place: ① The goal of forest genetic breeding has changed. From the single pursuit of forest growth in the past to the pursuit of various economic benefits and adaptability; The understanding of space has also changed. The academic circles realize that there is a lot of radiation in space that is difficult for human experiments to simulate. Therefore, experts are increasingly looking forward to changing the quality traits such as color and particle size of forest seeds controlled by a single gene, in order to seek new breakthroughs in the field of forest genetic breeding. This is the result of the development of the times and forest genetic science. As early as 1950s, the forest products industry began to study artificial mutation. After the mutation of Populus tomentosa by human low temperature radiation, the leaves are notched and hairless, but the growth has not changed. The growth cycle of trees is long, with only half a rotation period in ten or even decades. It is difficult to confirm the influence of radiation in a short time. However, while engaging in other scientific research, it should be of theoretical value and practical significance to choose suitable forest seeds and plant materials to send to the sky and study the effects of space radiation. Sending small seeds and pollen to the sky is a realistic measure. In order to facilitate the experiment, it is best to fly pollen of different tree species and seeds of different sizes together for comparative study. Although it is difficult to explain the problem of forest seeds going to heaven at present, I am full of confidence and expectation for its prospect.
Edit the principle of genetic variation in this paragraph.
Safety of space breeding
Space food is no different from ordinary food and is very safe. Regarding the safety of space food, experts generally believe that space breeding has not introduced foreign genes into crops to make them mutate. As a mutation breeding technology, space breeding can cause gene mutations such as chromosome deletion, replication, translocation and inversion in crops. This variation is the same as the natural variation of natural plants, but the time and frequency have changed. In essence, space breeding only accelerates the natural variation that takes hundreds or even thousands of years in the biological world. The intense radiation of cosmic rays in space is an important condition for plant genetic variation. At present, the radiation dose in artificial radiation breeding is only a few tenths of the international food safety radiation dose, while the radiation dose in space is less than 1% of the radiation dose in radiation breeding. Genetic variation caused by cosmic rays often reminds people of genetically modified foods. Transgenic crops are new varieties cultivated by introducing foreign genes into plants. For example, genetically modified soybeans are mutations produced by introducing genes from non-soybean plants, even animals and microorganisms. Space breeding is to mutate the seeds of crops without introducing foreign genes. The Regulations on the Safety Management of Genetically Modified Organisms promulgated by China specifically excludes the management of new species produced by mutation, which also shows that space breeding is very safe and there is no need to worry about the safety of its products. Space food is selected according to human needs, not genetically modified food. As for pollution, it is the way of planting and the use of pesticides and fertilizers.
Application examples of space breeding
Space breeding has been applied to some extent. The fruit of space pepper is much larger than that cultivated on land, and its taste, weight and shape have changed. Space cucumber flight 1 has passed the national variety approval. The maximum fruit weight 1 800 g, length 52 cm, Vc content increased by 30%, soluble solid content increased by about 20%, and iron content increased by 40%. It shows that space mutation can obtain mutants with high nutritional content and good taste. Space vegetable gourd is 75 CITI long, with an average fruit weight of about 4 kg and a maximum fruit weight of 8 kg, which contains momordicin for treating diabetes. The average fruit weight of space tomato is about 350 g, the maximum fruit weight is 375 g, and the yield is about 75 000 kg/hm2. In addition, the long eggplant carried in space weighs 350 g and tastes very fresh and tender. The soluble solid content of space sweet pepper 872 was increased by 20%, and 1 yellow progeny and 1 red progeny were obtained in space sweet pepper, and the space five-color pepper series was obtained, which was different from the yellow and red sweet peppers obtained by space mutation. Although the prospect of space breeding is attractive, the industrialization of this cause is not satisfactory at present, and many achievements are still in the pilot stage and small-scale production stage. According to statistics, taking the rice with the most space breeding as an example, the best variety has only been popularized by 200,000 hm2, which is far from the scale of popularizing tens of millions of hme in hybrid rice. It should be noted that space breeding is a brand-new interdisciplinary subject, involving many fields, such as space technology, radiation technology and biotechnology. And it is not very mature and perfect. After all, there is little space flight, mainly rice and wheat. Because China is a big agricultural country with 1, space breeding technology has been paid attention to. Although China is not 1 for aerospace technology, it should be 1 for aerospace agricultural breeding. Generally, it takes 8 years for hybrid technology in conventional breeding to obtain new varieties, and space breeding can shorten the time by half. After being brought back from space, it must be cultivated on the ground for no less than 4 generations. Space breeding is 1 a good way to shorten the breeding cycle.
Influencing factors of editing this paragraph
Seed purity
At present, the purity of seeds should be tested first at home and abroad to ensure the purity of seeds. After carrying it back, it is necessary to carry out ground 1 trial planting. Morphological characters, such as plant height, growth, etc., will certainly show a large number of character separation at the time of emergence, and should be detected every 1 plant. When the mutant plants are selected for the second generation, there is still great character separation, all the bad characters are eliminated, and the excellent mutant offspring are planted to the third generation. After the third generation planting, the seeds with the best characteristics are collected, and the fourth generation planting is generally stable, that is, 1 stable new variety is obtained.
growing environment
Special attention should be paid to the growth environment during seed growth. Phenotypic degradation of many varieties is not real variety degradation, but because the surrounding pollination environment is not good. For example, the pollen planted next to space pepper is not space pepper, and its offspring may restore their original characteristics. Therefore, the key to maintain the excellent characters of space pepper is to create a good breeding environment for it.
Spatial residence time
Aiming at the influence of staying time in space on the results of space breeding, South China Agricultural University conducted the following experiments: arranging seeds in sequence on the nuclear excitation board, and after the seeds come back, the number of times the seeds are irradiated by high-energy ions can be detected from the nuclear excitation board. Because the precision of space breeding is difficult to control and has certain blindness, the number of times that seeds are hit by high-energy ions is not as good as possible, and the time spent in space is not as long as possible. As long as high-energy ions can accurately hit the DNA chain of seeds and combine in the direction needed by human beings. The results of space breeding have little to do with the time spent in space. China will receive tomato seeds from the Mir space station for six years, and the performance of its descendants will not be better than that of China's spacecraft for more than 20 days. This is precisely because there are many radiation conditions in space that are difficult to simulate in human experiments, and it is impossible to artificially control the intensity or dose of radiation in space at present. After all, the radiation of high-energy ions is random. Space breeding must cooperate with conventional breeding methods such as field observation and selection, which are inseparable, and molecular detection methods are also available.
Research progress of editing this paragraph
According to statistics, the mutation rate of general seed space is only between 0.05% and 0.5%, and many seeds have not changed at all. Jiang Xingcun, a former researcher at the Institute of Genetics of Chinese Academy of Sciences and known as "the first person in space breeding in China", told reporters that space breeding mainly induces genetic variation of plant seeds through comprehensive space environment factors such as strong radiation, microgravity and vacuum. Because for hundreds of millions of years, the morphology, physiology and evolution of plants have been influenced by the earth's environment, once they enter space, they may produce genetic variations that are difficult to obtain on the ground. High-quality varieties were selected from the items brought back by satellites, and the fruit size, nutritional components and plant insect resistance were significantly improved. Plant seeds can mutate as long as they are sent into space? Can the grown vegetables and fruits increase production? The propaganda of space breeding now often makes people yearn for the magic of space breeding. Professor Sun, director of the Institute of Environmental Systems Biology of Dalian Maritime University, said that it does not mean that as long as seeds are in space, they will definitely mutate. And the mutation rate of different varieties is also very different. According to statistics, the variation rate of seeds is generally between 0.05% and 0.5%, and many seeds have not changed at all. Among the mutations, not all are beneficial mutations such as enhanced disease resistance, high yield and early maturity. Even on the whole, there are more bad mutations such as reduced yield and weakened disease resistance, because space is a special extreme environment after all. In fact, the so-called "good" and "bad" mutations of seeds are artificially selected, and the mutation itself does not matter whether it is good or bad. When doing basic research, many "bad mutations" are more conducive to studying the sensitivity of seeds to space environment and the mechanism of gene repair.
Edit this spatial breeding achievement.
Since 1987, China has carried out 10 for many times by using recoverable satellites and shenzhou spaceship, and put 1000 kinds of seeds and biological materials into the sky. Because plant seeds are small in size and easy to carry, there is a great choice in cultivating new varieties. The grain crops transported are: wheat, rice, soybeans, corn, mung beans, peas, sorghum and so on. Vegetables: tomatoes, peppers, cucumbers, beets, eggplants, radishes, etc. Cash crops include cotton and tobacco. Flowers include marigold, cockscomb, tricolor hibiscus, black nightshade, lotus, lily and so on. Chinese herbal medicines include Radix Astragali and Radix Glycyrrhizae; Tree species include Pinus tabulaeformis, Pinus bungeana, Asparagus and lawn seeds. Through space breeding, a number of new mutant types and new varieties with excellent characters have been cultivated. For example, rice seeds are carried by satellite, which has the characteristics of plant height variation, strong separation, full panicle type and short growth period. Increase production by 20%, and yield per mu in a single season is 400-600 kg, with a maximum of 750 kg. Protein content is increased by 8%-20%, and total amino acid content is increased by 53%. Space wheat is a high-yield type, which has the characteristics of dwarf, early maturity, lodging resistance, disease resistance and high protein. Space green pepper has thick branches and leaves, big fruit and thick meat, and strong immunity. The weight of a single fruit is 350-600g, and the yield per mu in a single season is 3500-4000mg, up to 5000mg, which is 20%-30% higher than that of ordinary green peppers. According to the detection and analysis of Institute of Genetics, Chinese Academy of Sciences, the content of vitamin C in space green pepper increased by 20%, the content of soluble solids increased by 25%, and the disease index decreased by 55%. Space cucumber, full of vines, is very big, with a single fruit weight of 850-1100g, and has strong disease resistance. In particular, the female flowers are much more open, which is 1.5 times that of sweet potato seedlings. Although its skin is a little thick, the melon meat is very cool, juicy and tender. The growth of space tomato is particularly gratifying, with plant height, stem diameter and more ears, which is more than 15% higher than that of conventional tomato, and the highest yield can be increased by 23.3%. The "Yufan 1No." bred by Horticulture Research Institute of Heilongjiang Academy of Agricultural Sciences has been planted in more than 6,543,800 mu nationwide. The sugar content of "space cherry tomato" is as high as 13%, which is equivalent to citrus. It tastes fresh and sweet and can be eaten as fruit. The remarkable characteristics of space watermelon are that the sugar content is above 13%, the soluble solids are increased, the fiber is less, the watermelon is big, and it tastes sweet and delicious. Space corn can grow 6-7 "sticks", grow 5 colors, and taste better than ordinary corn. Celosia cristata, chrysanthemum, Abelmoschus manihot, Petunia, etc. Spaceborne, all show the characteristics of many flowers, color variation and long flowering period. Especially the pink Petunia, with red and white stripes on its flowers. What is even more surprising is that the flowering period of marigold has been extended to more than 6 months. Garlic that swims through space can grow to nearly half a catty, and the seedlings of space radish keep pests at a distance. Indica rice and japonica rice, which could not be hybridized originally, can also be hybridized because they have crossed space. The benefits and achievements of space breeding have attracted the United States, Russia, Bulgaria, the Philippines and other countries, all hoping to cooperate with China. The space seeds that God "cultivated" and returned to the "Earth" have a very broad market, which will surely spread vast land, produce more and better space food, and bring infinite gospel to mankind!
Edit this paragraph. Do space plants dare to eat?
Ordinary green peppers, tomatoes and cucumbers on the ground have changed since they came back from the sky. A lot of people are a little nervous. Dare you eat these things? After testing and analysis by scientists, we can tell you responsibly that rice cultivated in space is still rice and green pepper is still green pepper. Without the introduction and integration of foreign biological genes, the species has not changed fundamentally. This is just like the gene arrangement of DNA is "1, 2,3,4", and the gene arrangement after space breeding is "1, 3,4,2", but the sequencing has changed. But there is a "5" in transgenic plants, so there is a saying that "potatoes taste like beef" and "pork tastes like spinach". It can be seen that there is an essential difference between space breeding and transgenic. Understand this truth, when you see cucumbers with thick arms and eggplants with big basketball after traveling in space, you don't have to worry too much, so you can eat with confidence. The United States once analyzed the tomato seeds and fruits carried by the space shuttle Columbia, and concluded: "It is non-toxic and edible." The Food and Agriculture Organization of the United Nations, the International Health Organization and the International Atomic Energy Agency jointly recognize that space seeds are safe seeds and the crops cultivated by space seeds are healthy food.
The significance of editing this space breeding
With the development of science and technology and national economy, human survival and production activities have entered the earth orbit space and outer space from the initial land, sea and atmosphere, and started to adapt, study, understand, utilize and develop the space environment, which is a great leap in the history of human civilization. The space environment contains extremely rich and diverse resources. As a new means of improved seed breeding, space breeding has economic and social benefits that cannot be underestimated. Space breeding is also a successful attempt to utilize space resources. Advanced space technology has opened up a new way for the rapid cultivation of fine varieties and special germplasm resources, and has shown a bright future for mankind to enter the era of space agriculture. The second and third generation space vegetables have shown the characteristics of high yield, disease resistance and high vitamin content. Space flowers have generally changed in flowering period, flower pattern, plant type and color. Some flowering periods are longer and some shorter. Purple flowers can turn into white and red. Humans should take advantage of the special value brought by these new varieties. Generally speaking, the seeds carried around the country are varieties with high local added value, local characteristics and large planting scale. After obtaining excellent varieties, industrialization will directly and significantly promote the local agricultural economy. For example, alfalfa, Misha, sainfoin and agropyron cultivated in Beijing by the Institute of Genetics and Developmental Biology of Chinese Academy of Sciences have the following characteristics: especially cold and drought tolerance. Alfalfa, in particular, has a high content of protein and can be cut one after another like leek. Compared with the unloaded control plants, it has a longer survival period and is not easy to wither. According to reports, experts will continue to screen and inoculate the space "grass people" with variation characteristics. Once their variation characteristics are stabilized, they will be planted on a large scale in western China and around Beijing to prevent grassland desertification and intercept sandstorms. High quality varieties have considerable market prices. It is reported that American space tomatoes are more expensive than high-quality apples. Space breeding can shorten the breeding cycle. According to experts, normal agricultural breeding generally takes eight years, and space breeding can shorten the time by half. However, after being brought back from space, it must be planted on the ground for four generations to cultivate a variety with stable performance.
Edit the development prospect of this paragraph.
For the future development prospect of space breeding, we should focus on the ecological restoration plants in the western development. Because to support the northwest region, there must be a large number of forage grass, sand-fixing herbs and shrubs, cold-resistant and drought-resistant tree species, as well as energy plants and Chinese herbal medicines. Vegetables should bring good vegetable seeds. Flowers are mainly test-tube seedlings with high added value. In terms of trees, Shenzhou IV spacecraft is equipped with three economic tree species: Castanopsis kawakamii, poplar and yew. In the future, China will continue to carry tree species, and at the same time, it will also introduce tree species carried by Mir space station from Russia. The effect of seed mutation is mainly related to the dose, time and location of radiation in space, and has nothing to do with what seed it is. The seeds returned from space have been cultivated, and the selected excellent varieties should be planted for no less than four generations, and the genetic characters of each generation have been separated. If you are lucky, a new variety will be selected after 4 generations, which needs the variety approval of the relevant state departments. This process will take at least 3 years, and then the experts can pass the examination to get the certificate. Objectively speaking, on the question of whether to carry woody flowers and trees seeds, space breeding in forest genetics and breeding circles
The response is not very urgent. There are many reasons, the most important of which is the characteristics of woody plants themselves. Many experts in forest genetics and breeding believe that the seeds of 1 and 2-year-old plants are more sensitive to external stimuli than perennial woody plants. The long growth cycle and high biomass of trees make the research on forest genetic breeding much more difficult than that on crops. Mutation breeding is also of great value in herbaceous flower breeding. The mutated flowers can become grotesque and improve their ornamental value. However, tree breeding is different. People's expectations of trees are more quantitative traits, especially the growth, which are controlled by quantitative genes. According to the hypothesis of minor polygenes, there are many quantitative genes in forest trees, and the change of one or several genes has little significance for improving the quantitative traits of forest trees. A lot of experiments done by experts have proved this point, which may be one of the reasons why forest genetic breeding experts are not optimistic about carrying forest seeds for a long time.
Editing this paragraph is controversial.
"Space breeding" is not superior to ground breeding in terms of comprehensive factors. What are the main effects of space environment on plant physiology and heredity, what factors contribute to these effects and how to produce them are still inconclusive. Therefore, the space breeding program has caused some experts' arguments since it was launched. Fang, a doctor of molecular biology, once said that "space mutation" is essentially the same as other mutation methods and cannot have any advantages. The so-called "space breeding" is not more advantageous than ground breeding, but occupies valuable space resources, which is totally hype and should be denied. Fang said that the directionality of mutation was first observed in genetic experiments and later confirmed by basic research of molecular genetics. When we treat seeds with radiation and drugs, we are blindly attacking the DNA in the seeds. What changes will happen to DNA sequence or structure is unpredictable, so how they will change the function of organisms is also random. Due to the long-term evolution of organisms, the relationship between their structure and function has been quite perfect and coordinated, and blindly changing it will be harmful or useless in most cases. Only by chance will there be some beneficial mutations that we are happy to see. Getting Started Atlas More Atlas
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