Why send the seeds into space and plant them down again. What’s bigger?

Although the media often report that the space fruit is the seed that carries a spacecraft, experiences the space environment and then returns to the earth’s surface. But in fact, the cultivation of space fruit is not a simple “carrying”, but a series of tedious screening and cultivation. < p > < p > first of all, seeds flying on spacecraft should be strictly screened. Only those varieties with good genetic stability, strong disease resistance and high yield can be qualified to enter space. < / P > < p > the reason why the fruit will become bigger after entering space is that the space environment is very bad. We know that the sun will emit ultraviolet rays and solar wind. They are high-energy particles, which can destroy genetic material and cause gene mutation. The reason why we can’t feel this change is that the earth has a geomagnetic field that can guide the solar wind to the north and south poles of the earth, and the ozone layer can isolate ultraviolet rays, so our living environment is relatively stable and safe. < / P > < p > because of this, on earth, the probability of biological gene mutation is low, only about one in 200000, and it is unpredictable; but in space, the probability of biological gene mutation is very high, generally several percent or even one thousandth, but the probability of favorable gene mutation is only one thousandth to one thousandth. Compared with the earth environment, the probability of mutation is very high. < / P > < p > although space seeds are not 100% prone to gene mutation, when they return to earth, no one knows which one of them has a gene mutation. At this time, it is necessary for breeders to cultivate them and select some individuals with gene mutation. < / P > < p > we know that there is no direction for gene mutation. At this time, organisms may suddenly become harmful individuals, such as symptoms of low disease resistance, or they may suddenly turn into beneficial individuals, such as bigger, sweeter, etc. < / P > < p > breeders will pick out the favorable gene variants, continue to seed and screen, and then let them self breed. It is possible to cultivate at least four generations of crop varieties for more than four years. < / P > < p > the space fruits cultivated at this time have sweeter fruits, more colorful fruits and larger individuals. But when the media reports, they like to report the eye-catching species. Because the fruit is sweeter and needs to be tasted on the spot, it is difficult for people in front of the television to feel it; and the brighter color is not as bright as the big one, so the media always like to report the bigger space fruits. So we fall into the survivor bias and think that all the space fruits are big 。 Space fruit is just a way of breeding. Before there was no space breeding method in the past, breeders also used physical or chemical methods to induce gene mutation in plants. For example, the cultivation of seedless watermelon. Scientists treated watermelon seeds with colchicine to mutate their genes into tetraploid plants, and then crossed them with diploid plants to obtain triploid progenies. Because the triploid plants will produce disorder in association, they will not produce offspring, thus forming seedless watermelon. In addition, breeders will use backcross, self cross, test cross and cross to induce more dominant individuals. That is to say, although the fruits of space are magical, we have been able to cultivate many excellent biological varieties before there is no space breeding method. < / P > < p > moreover, if only space breeding did not involve the efforts of breeders, we would not have harvested so many varieties of space plants. In other words, what is really powerful is not space breeding, but the hard work of breeders. It is a large number of breeders like Mr. Yuan Longping who are constantly cultivating new varieties and selecting new varieties in the field. Only in this way can we harvest so many high-yield plants, and the earth has no energy crisis. ASMC, a lithography maker, was one of TSMC’s 14 top suppliers last year