"Space mutation breeding" began in the 1960s. At present, only the United States, the Russian Federation and China have successfully carried out space-borne breeding. In China, 1987 launched the seeds of vegetables and other crops into the sky by satellite, and the recoverable satellite launched more than 10 plant seeds, carrying more than 1 000 varieties. More than 500 varieties have undergone genetic variation, and some new crop varieties, strains and germplasm with high yield, high quality and multi-resistance have been cultivated, many of which are excellent with breakthrough influence. 10 years, China has made rapid development and remarkable achievements in space mutation breeding.
Practice has proved that space mutation breeding is an effective way to quickly cultivate excellent new varieties. Guangxi, Fujian, Zhejiang, Jiangxi, Guangdong, Hunan, Heilongjiang and other provinces have approved and popularized space rice varieties on a large scale, but the space rice breeding work in Hubei Province was carried out late and did not receive enough attention from Hubei breeders.
According to the actual situation of rice breeding and the breeding of new high-quality rice varieties, the Institute of Grain Crops of Hubei Academy of Agricultural Sciences carried four high-quality rice breeding materials on Shi Jian-8 satellite, and initially carried out space mutation breeding of rice.
1 Concept and principle of space mutation breeding technology
Space mutation breeding, also known as "space mutation breeding", uses a recoverable satellite or spacecraft to send crop seeds or experimental mutagenic materials into space 200 ~ 400 kilometers away from the earth, and uses the strong radiation of space cosmic rays to carry out mutation treatment in special environments such as high vacuum, microgravity and alternating magnetic field, so that the carried crop seeds and materials generate favorable mutations, and then continues to adopt conventional breeding techniques after returning to the ground for trial planting. Therefore, space mutation breeding technology is a brand-new breeding technology combining space technology, biotechnology and crop breeding technology.
2 the significance of space mutation 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, ocean 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.
Excellent varieties are the decisive factor of agricultural development and play an irreplaceable role in increasing crop yield and improving crop quality. At present, the vast majority of new crop varieties in China are cultivated by ground breeding for several years under conventional conditions. Combining aerospace, the most advanced technical field, with agriculture, the oldest traditional industry, and using space mutation technology for crop breeding are of great significance for accelerating the pace of breeding in China, improving the quality of breeding and exploring new fields of breeding research with China characteristics.
Rice is one of the most important food crops. More than 65,438+0/3 people in the world live on rice. China is a big rice producer and a big rice consumer in the world. The planting area of rice accounts for 1/3 of the planting area of grain crops, and the output accounts for nearly 1/2 of the total grain. Therefore, rice has become the key selection object of space breeding. China has cultivated new rice varieties with high yield, high quality and disease resistance through space breeding, which is of great significance to increase grain production and farmers' income.
Research and application progress of space mutation breeding technology at home and abroad
3. 1 Research Progress of Foreign Space Mutation Breeding
Foreign research on space mutation breeding began in the 1960s. In recent years, space powers have not only returned to satellites and space shuttles, but also conducted biological experiments on crop seeds in built space stations. For example, the Russian Academy of Agricultural Sciences and NASA have successfully planted space wheat in the space greenhouse of the Mir space station. Through the research and application of space mutation breeding technology, various space powers have successfully cultivated more than 100 new varieties of production crops, which not only laid the foundation for the theoretical research of space mutation breeding, but also opened up broad prospects for the development and application of space mutation breeding technology.
According to incomplete statistics, during the 40 years from 1957 to 1997, * * launched 120 satellites for space life science research, with 38 recoverable satellites (times), including 0/6 from the former Soviet Union and 65,438 from the United States.
3.2 Progress of Space Mutation Breeding in China
China is the third country in the world to master recoverable satellite technology. Previously, 22 recoverable satellites have been launched and 2 1 satellite has been successfully returned. Since 1978, many on-board experiments have been carried out on 10 by using recoverable satellites, and a number of new crop varieties, strains and germplasm with high yield, high quality and multi-resistance have been successfully cultivated. China has entered the advanced ranks in the world in the experimental research of space mutation breeding and the mechanism research of plant cytology, physiology and molecular biology.
On July 22nd, 2006, the Commission of Science, Technology and Industry for National Defense held a factory verification meeting of China's first space breeding satellite-Shijian-8 breeding satellite. It will be launched by Long March II rocket at Jiuquan Satellite Launch Center in September 2009, and will return to the ground after flying 15d. The satellite carries more than 2,000 seed materials of 9 categories 180 groups. Seed materials mainly include food crops, cash crops and feed crops, as well as microbial strains and molecular biology materials.
According to the person in charge of the Commission of Science, Technology and Industry for National Defense, Shi Jian-8 space breeding satellite will combine the mature recoverable satellite technology and mutation gene technology in China, launch a special satellite for breeding, conduct in-depth research on space breeding, and comprehensively explore the mechanism, methods and theories of space breeding technology in combination with experiments of simulating space environmental factors on the ground to cultivate excellent varieties.
4 characteristics of rice space mutation breeding
Compared with conventional breeding methods, space mutation breeding method has obvious advantages and characteristics. First, some varieties have high variation frequency, large variation range, increased beneficial variation, and most variation traits are stable and rapid. The results of Li Yuanxiang's rice breeding research show that there is a strong broad-spectrum separation of main agronomic and economic characters among the second generation population. The variation of various characters is the opposite direction of advantages and disadvantages; Some characters develop in a favorable direction; Some have physiological variation, and the variation cannot be preserved to future generations; Some have genetic variation, and their excellent properties can be inherited stably. Second, the breeding cycle is shortened. It takes an average of 10 years to obtain a new variety through traditional breeding, and the 5 ~ 6 generations tend to be stable. Space breeding only takes about 5 years, and it tends to be stable in 3 ~ 4 generations. Thirdly, there are some favorable special mutants among plants, which are difficult to obtain by mutagenesis of other physical and chemical factors on the ground. For example, the mutant line of japonica rice fertility restoring gene created by space breeding can restore the fertility of indica rice male sterile line, and the obtained characteristic rice (purple rice and brown rice) is a rare mutation that is difficult to obtain by other ground mutation breeding methods at present.