How seedless watermelons are grown
Do you know this? The process of how seedless watermelons are grown and the related aspects of cultivating seedless watermelons in green plants, the following is a comprehensive introduction.
In the hot summer, is there anything more pleasant than eating a few slices of cool, sweet, and juicy watermelon?
Of course, there is! That would be eating a few slices of cool, sweet, and juicy seedless watermelon.
Seedless watermelon
This is one of the reasons why seedless watermelons are considered one of the greatest inventions of all time. But there is a contradiction here, just like the famous question of "which came first, the chicken or the egg." As we all know, watermelons reproduce through seeds, and perhaps many friends have had the experience of accidentally or intentionally throwing watermelon seeds into a flowerpot or yard, only to see watermelon seedlings grow and eventually produce small watermelons. So the question arises, how do seedless watermelons come into existence without seeds?
It requires substances that can alter the genome of watermelons, and at the same time, plant three different genotypes of watermelon plants. A similar method can produce various seedless fruits, does it sound magical?
About 5000 years ago, the wild ancestors of watermelons grew in Africa, producing small, bitter, and hard fruits. After centuries of selection and breeding, watermelons gradually became the sweet, large, and juicy red fruits we enjoy today, with black, shiny seeds.
Then, about 80 years ago, Japanese scientists directly created a seedless watermelon variety by modifying the genome of watermelons. They used a process called "mutation breeding": exposing the plants to an environment (such as strong radiation) to induce changes in their genome and then selecting the offspring with the desired qualities.
In 1939, scientists used a chemical called colchicine, which, when applied to plant cells, prevented the cells from properly separating the double DNA produced by cell division, leading to doubled DNA in the cells. Normally, animals, including humans, cannot survive with an abnormal number of chromosomes (DNA), but plants seem to be unaffected by this. A professor at Kyoto University in Japan used colchicine to cause a normally diploid watermelon plant to produce tetraploid watermelons. Then, he had the brilliant idea of crossing diploid and tetraploid watermelons to obtain seeds with triple DNA. However, planting this genetic monster was not the last step in creating seedless watermelons, as the flowers did not produce fruit normally. Therefore, to obtain seedless watermelons, artificial pollination must be performed, that is, using mature pollen from normal diploid watermelons to stimulate the ovary of the triploid watermelon to develop into fruit. The resulting watermelon is seedless.
Does this sound complicated? And since triploid watermelons have no seeds, they cannot be used to continue producing seedless watermelons. This means that to continuously produce seedless watermelons, it is necessary to maintain the cultivation of both diploid and tetraploid watermelons and use them for breeding during the繁殖 period. This requires planting three different varieties of watermelons simultaneously and a considerable amount of manual intervention. Although it sounds like a lot of work, people love seedless watermelons, and with a market for them, the effort is worthwhile for farmers.
How seedless watermelons are grown
Seedless watermelon production process diagram
Now, researchers have tried various methods to make the processing smoother, for example, they have developed diploid plants that do not produce female flowers, so farmers can plant them to obtain pollen without worrying about accidentally producing any seeded watermelons.
Today, watermelons are not the only seedless fruit; through similar DNA doubling operations, we have produced seedless grapes, seedless oranges, and seedless bananas, among others. This sounds counterintuitive, as we have never considered any of them as genetically modified organisms, even though they have indeed been genetically altered. Only crops like modern genetically modified soybeans are referred to as "genetically modified."
The above introduction to how seedless watermelons are grown and a brief description of the cultivation process of seedless watermelons is provided for everyone's learning and understanding!