Shulou(Shulou.com)11/24 Report--

I wonder if you like broccoli? Broccoli is nutritious and inexpensive, so it is also called "the doctor of the poor". Because there are many broccoli lovers, China has become the country with the largest planting area of broccoli in the world.

But did you know that most of the broccoli eaten by people all over the world, including our country, are provenances bought from a Japanese company? What on earth is going on?

It all started with a seed company called Sakata.

Sakata broccoli seeds have a global market share of 65 per cent and 70 per cent, according to Matt Linder, west coast sales manager at Sakata us. According to the China Rural Development report (2021) released in August 2021, China's import dependence on broccoli is more than 80 per cent. Sakata can be said to have monopolized the global broccoli provenance market.

Broccoli (Brassica oleracea var. Italica (Photo: wikimedia) also accounts for 70% of the broccoli seed market, the price of its broccoli seeds can be said to be "ridiculously high".

Li Zhanjiang, an associate researcher at the Institute of vegetables and Flowers of the Chinese Academy of Agricultural Sciences, pointed out that under normal circumstances, the price of 100,000 seeds of broccoli is about 5500 yuan, that is, less than 5500 yuan per jin.

A certain type of Sakata broccoli seed (photo source: sakataseed.cn) when you see here, I believe you will have a question: can't you continue to plant the second generation seeds when the seeds germinate and bear fruit? How did Sakata make it impossible for buyers to grow new broccoli seeds from their own seeds?

In fact, they are using plant male sterility technology (CMS).

Male sterility in plants is also called male sterility, which means that male flowers that produce pollen (sperm) are waste, waste food but useless, and have no way to fertilize the pistil.

So you see, even if broccoli is planted with Sakata's broccoli seeds, there is no available "boy flower" to produce second-generation broccoli. And if you pollinate with the pollen of any kind of broccoli, you don't know what ghost it is.

Therefore, this kind of broccoli seed is equivalent to one-off, and the "source code" (that is, seed line) of broccoli that can steadily produce the same quality seeds is in Sakata's hands, so farmers have to buy their own seeds all the time.

(photo source: pexels) of course, it is not Sakata's originality to use plant male sterility technology to avoid copying one's own provenance.

In fact, the history of plant male sterility can be traced back to 200 years ago, which was discovered by German botanist Joseph Gottlieb K ö lreuter in the 18th century, and his research later became the basis of plant male sterility technology.

Humans whose brains emit intelligent light have found that the use of male sterility in plants can not only prevent males from producing fertile pollen, play the effect of provenance protection, but also cultivate "X-Men" in plants.

Yes, another great use of male sterility in plants is to stabilize the familiar heterosis.

Hybridization is relatively easy for animals, but it is a difficult problem in the plant world. This is because plants are different from animals, many plants are hermaphroditic, similar to "hermaphroditic", so the pollen of "I" is easy to fertilize "me", which is called self-crossing.

If the pollen is active, it will be difficult to prevent self-crossing. On the other hand, if the pollen is like a "Qing palace eunuch", then self-crossing will not be possible, so male sterility has become a sharp weapon to ensure hybridization.

In fact, in addition to broccoli, most of the cabbages, watermelons, melons, sweet corn, tomatoes and chili peppers we eat are cultivated through plant male sterility.

The hybrid production magic commonly used in cruciferous Brassica crops (such as cabbage, cauliflower, broccoli, radish, mustard, rape) is called Ogura plant male sterility (Ogura-CMS).

Unexpectedly, broccoli (right 2), cauliflower (right 1) and cabbage (left 1) belong to varieties of the same species, all artificially bred by wild mustard (Brassica oleracea). (photo Source: vox.com) when you see this Ogura, some students who have a basic knowledge of Japanese may wonder if it has anything to do with Japan if there is a Roman word in Japanese in this technology.

Yes, the male sterility technology of Ogura plants does originate in Japan and was discovered by Hiroshi Ogura in 1968. At that time, he noticed that some wild radish in Japan had male sterility.

The flowers of plant male sterile Japanese radish (left) and fertile Japanese radish (right) are compared on a scale of 1 cm. (photo Source: doi:10.1270 / jsbbs.64.38) since the male sterility of cruciferous plants is inherited through genes in the mitochondria of the "mother", which only affects the "son" and not the "daughter", the male sterile mitochondria carried by Japanese radish belonging to Cruciferae can make other plants lose their male reproductive ability. In this way, the cytoplasm of Japanese radish is used to cross species with cruciferous crops such as broccoli and cauliflower to produce "eunuch" crops.

(photo source: wikimedia) and the birth process of this cross-species "love crystallization" is very expensive and time-consuming.

At first, male sterility in plants relied on sexual hybridization (sexual hybridization), in which the pistils of another species were pollinated with pollen from different species, and then the first generation of hybrid seeds were obtained. The Ogura type plant male sterile crops obtained by sexual hybridization have the cytoplasm of Japanese radish and the nucleus of "native vegetable". However, the flowers of cruciferous plants are generally mini, and the process of pollinating them is really too laborious.

Have you ever seen flowering broccoli? (photo source: publicdomainpictures.net) second, although hybrids have advantages, they are "damned"-it is difficult for cross-species seedlings to survive in the natural environment. As a result, hybrid seeds often need to be rescued by embryo rescue, which is to put the seedlings in an artificial environment similar to an incubator for premature babies to spend the most difficult "childhood".

The process of saving embryos from wheat and intermediate wheat grass (Thinopyrum intermedium) hybrids: the embryos were removed from the seeds and cultured in the medium. (photo Source: wikimedia) however, a more severe method of male sterility has emerged in recent years, that is, plant somatic hybridization (somatic hybridization) is used to obtain male sterile plants.

The leaf cells (green) of morning glory (Petunia sp.) and the petal cells (pink) of New Guinea Impatiens (Impatiens neuguinea) were fused by somatic hybridization. (photo Source: wikimedia) somatic hybridization is to skip the step of pollination and manually fuse somatic cells of different species into unnatural hybrid plants with some kind of plug-in. The plant obtained by this technique is also called cybrids. The Sakata company mentioned above applied for a patent for the seed of cytoplasmic hybrid broccoli as early as 1997.

It turns out that contemporary cabbage, cauliflower and broccoli are not their own vegetables except the nucleus. After watching the miraculous modern agriculture, I wonder if you can taste something different the next time you eat food.

Buyer: how's your seed?

Seller: "no queen" worry.

Reference:

Https://docs.qq.com/doc/DVFZWWFZlSnlBaVFD

This article is from the official Wechat account: take Science Home (ID:steamforkids), written by Seven Jun

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