But in fact, friends who know about breeding know that space pepper is just a name, and the bitterness behind it is only known by breeding engineers, because although it is called space pepper, it does not mean that green pepper seeds will become high-yield after passing through space!
So-called space breeding
Space breeding is also called space mutation breeding. The specific operation is not complicated. The method is to send crop neutrons or test-tube seedlings into space through sounding rockets or satellites, expose them to the radiation of the sun and cosmic rays, mutate neutron genes, and then return to the earth to germinate or continue planting, confirm their growth and results, and select excellent ones to enter the breeding process!
But in fact, this mutation is uncontrollable, and the impact under high energy radiation is random. For example, some mutations will not produce high yield, but will affect growth and development! However, some are not obvious at all. Only a few seeds will develop in the direction we want, and breeding is not just a good generation that can be used as seeds. To maintain this advantage, breeding engineers need to do a lot of work.
Therefore, space breeding is not an easy task, and with the development of modern breeding technology, space breeding is no longer our preferred breeding method, but only as a breeding option because of the development of other more efficient technologies!
What other excellent breeding methods are there?
Common breeding methods include mutation breeding, haploid breeding, hybrid breeding, polyploid breeding and transgenic breeding, but no matter which method, the genes of species must be changed, otherwise the same seeds will be obtained. So which of these farming methods is the best?
In fact, space breeding is an inefficient mutation breeding method, and a large number of screening is needed in the later stage to cultivate a new variety. We saw the tall green pepper and wondered how much sweat the engineer contained!
Molecular breeding
There is a precision breeding technology in modern breeding methods, but it is different from transgenic breeding. This is a rapidly developing molecular breeding technology in recent years, which directly introduces the genes of excellent species into recipient cells and accurately controls the morphology that new varieties want to show in the future, such as lodging resistance, insect resistance, high yield, drought tolerance and cold tolerance.
But the premise is that the detectable DNA sequences or protein (molecular markers) showing these shapes must be accurately labeled, which is obviously different from transgenic, because molecular markers only involve sequencing, detection and single nucleotide polymorphism, which is obviously different from transgenic!
Molecular breeding can also overcome the incompatibility of distant hybridization and show their respective advantages in a variety. Another advantage is that molecular breeding can be inherited, which means that the seeds of new varieties will gain the advantages of the female parent and can be planted.
Transgenic breeding
By adding one or more genes into the genome of another organism through modern molecular biotechnology, the technology of improving biological characteristics is excellent, but its horizontal gene transfer range is very limited, and transgenic technology can expand this range and even achieve the purpose of excellent gene transfer between different species!
1983, tobacco, the world's first transgenic plant containing antibiotic antibodies, was successfully cultivated in the United States.
1992 China planted transgenic tobacco resistant to cucumber mosaic virus in field production for the first time, becoming the first country in the world to plant transgenic crops commercially.
In 20 12 years, the global planting area of genetically modified crops reached about1700,000 hectares. According to the statistics of planting area, about 8 1% of soybeans, 35% of corn, 30% of rape and 8 1% of cotton in the world are genetically modified products.
Schematic diagram of transgenic breeding
crossbreeding
The history of cross breeding is long, and the history of animal cross backcrossing is earlier. Because the breeding process can be seen intuitively, people will consciously carry out cross experiments! But the research of plant hybridization and backcross began with Mendel. However, it is depressing that Mendel's book "Experiments of Plant Hybridization" was published in 1866, and nobody took care of it for thirty years. It was not until the beginning of the twentieth century that biologists engaged in the same research that Mendel's contribution to plant hybridization experiments was discovered!
The way of cross breeding is easy for everyone to understand. After all, we are already too familiar with hybrid rice, and Yuan Longping's contribution in this respect is particularly outstanding. The simple understanding is to choose the best by hand after hybridization, and then choose to keep or further self-cross, and then choose the best according to the reserved traits, but in general, it takes at least several times of hybridization to get the target variety!
There is also a situation of backcrossing after hybridization, which is actually a kind of hybridization, except that the female parent or the male parent who hybridized for the first time hybridized again according to different needs, but according to different logical forms, statistical optimization is needed, and this workload is very large!
Finally, there is a question to remind. Both hybridization and molecular breeding support seed retention, but the second generation seeds are seriously degraded, because in the process of flowering and fruiting, the genes of the original varieties will gradually degrade, and the more generations, the more serious the degradation! Theoretically, transgenic varieties can operate non-germinated seeds. The so-called "childlessness" technology exists, but it only keeps the neutrons of plants from sprouting, and has nothing to do with childlessness in a broad sense. Don't associate it with it.