In 2018, at the 3rd International Sea Rice Forum, Mr. Yuan Longping talked about China’s vision for the future development of sea rice. He said that seawater rice strains have gradually matured. In the next 8-10 years, China's seawater rice planting area will develop to 100 million acres, and 30 billion kilograms of seawater rice will be produced every year.
It was also from that time that reports related to "sea rice" began to appear frequently in the public eye. Now more than 10 provinces across the country are promoting the planting of sea rice.
However, many people have a misunderstanding about seawater rice, thinking that it is rice that can be irrigated with seawater.
In fact, the name "sea rice" is indeed somewhat confusing. Its more accurate name should be saline-alkali tolerant rice. It is not rice irrigated with seawater, but a rice variety that can grow on land with a salinity between 0.3% and 0.8%.
The salinity of seawater usually reaches about 3.5%, and it is difficult for land plants to survive in this salinity.
The taste of rice usually depends on the variety and growing environment. Rice with good taste usually has higher amylose content and lower protein content, as well as the fertile place where it is grown [1].
Saline-alkali land is a typical barren land. At the same time, the rice produced by sea rice has a high protein content, so its taste is not very good.
In fact, before the establishment of Mr. Yuan Longping's "sea rice" team (Qingdao sea rice R&D team), sea rice has existed for a long time, but it was difficult to promote it due to poor taste and many other problems.
Even though many sea rice rice is more nutritious, original and healthy than ordinary rice, it has little market due to its poor taste, and its yield is not high, so farmers are not willing to grow it.
So, if this is the case, why is the country still vigorously promoting the cultivation of this kind of rice?
Is the rice of sea rice red?
We can see many people on the Internet saying that the rice of sea rice is as red as rouge. This is actually very misleading.
Sea rice is a typical hybrid rice. It has many varieties, and different varieties have different traits. As long as it has the trait of salt-alkali tolerance, it is called sea rice.
According to a report on China Popular Science Network, The colors of sea rice are very diverse, and they can produce purple, black, light yellow, or white rice, depending on their varieties [2].
Rice that is as red as rouge usually refers to sea red fragrant rice, which is a type of sea rice. It usually grows in saline-alkali land rich in selenium. Because it absorbs a large amount of selenium - the selenium content is 7.2 times higher than that of ordinary rice, the rice is dyed with a layer of red.
We mentioned before that there is some confusion in the name of "sea rice", but in fact they can really survive the short irrigation of sea water during high tide. Maybe this is the origin of the name of sea rice.
But they cannot be covered by seawater for a long time, otherwise they will still die due to infiltration. The salinity they adapt to is basically no more than 0.8% - this salinity is basically the same as our vegetable soup, and there is still a certain gap between it and seawater.
The specific reasons why seawater rice is salt-alkali tolerant are not yet completely clear, but at least 52 genes are known to be related to it.
Research reveals a new mechanism by which cell wall polysaccharide synthase improves salt stress tolerance in rice. Source: Chinese Academy of Agricultural Sciences
How did sea rice come from?
In fact, the research and selection of sea rice in China did not start very early.
As early as 1939, Sri Lanka had developed the world's first salt-resistant rice variety, Pokkali, and our country only began to invest in this research in the 1950s.
However, because our country’s hybrid rice technology is relatively advanced, many achievements have been made in sea rice research, far ahead of other countries.
Speaking of hybrid rice, what everyone thinks of must be the importance of wild rice.
If Mr. Yuan Longping's team had not discovered a wild male-sterile rice plant, then hybrid rice would be almost impossible to complete because rice is self-pollinating.
The same is true for sea rice. Those crucial genes usually appear in the wild, so it is particularly important to find wild rice that grows on saline-alkali land.
Chinese scientists have actually found a lot of salt-alkali tolerant wild rice, such as leek yellow, old yellow rice, etc. found in the Taihu Lake Basin, but the most famous of them should be "Haidao 86" discovered at the estuary of Zhanjiang, Guangdong.
Chen Risheng and his sea rice, photo source: Zhanjiang Daily
"Haidao 86" was produced in 198 It was discovered by scientist Chen Risheng in 6 years. At that time, he and his teacher Professor Luo Wenlie were surveying mangrove resources at Hutoupo Beach, Suixi, Zhanjiang, Guangdong, and then discovered the earliest "Haidao 86" - it was 1.6 meters tall and grew on the beach soaked in seawater.
Many people will take "Haidao 86" as an example when telling the story of China's sea rice. They subjectively believe that the origin of sea rice is due to the discovery of "Haidao 86".
Actually, this is definitely not the case. In the entire research and cultivation of seawater rice, Chinese scientists have not only used domestic wild salt-tolerant rice, but also introduced foreign strains for hybrid screening. This is normal operation and scientific research.
But from the current point of view, "Haidao 86" is definitely more important. I think a large part of the reason is that Mr. Yuan Longping's team chose to cooperate with Chen Risheng's team (I am not clear about the inherent genetic advantages of Haidao 86).
Why is the country vigorously promoting sea rice now?
In fact, from the fact that people began to pay attention to the cultivation of seawater rice in the early 19th century, it is not difficult to find that the development of seawater rice is of very high value.
One of the most critical values is the increase in grain production, because these rice can grow in saline-alkali land, and saline-alkali land cannot grow food crops.
Although our country is vast and rich in resources, many people may not imagine that our country is the world's largest importer of agricultural products. In 2021, imported grain will reach 164 million tons. It can be said that the jobs of 1.4 billion people are not completely in our hands.
This is why hybrid rice is so important to us (high yield). Although the yield of sea rice is not high, it can be planted in places where there is no grass.
If Mr. Yuan Longping's plan can be realized - the planting area of sea rice will reach 100 million acres from 2026 to 2028, then the increased food production will feed 80 million more people.
There are far more than 100 million acres of saline-alkali land in China - it is believed to be a full 1.52 billion acres. More importantly, normal farming will salinize the land, making the land increasingly unsuitable for growing ordinary rice.
The promotion of sea rice can make these barren lands more productive, making China's food security more secure.
The second key point is that the planting of sea rice can actually improve the land, turning the saline-alkali land into land that can be cultivated normally.
In 2021, seawater rice was planted in Pahatikeli Township, Xinjiang. Before planting rice, the soil pH value was 8.6 and the salinity was 0.2%. Food crops could not grow, and even if they grew, there was not much output. However, one year after planting seawater rice, the pH value dropped to 7.5 and the salinity was 0.15%. The soil improvement was very obvious.
In addition, another advantage of growing rice in saline-alkali land is that there is basically no insect pests in this place where no grass grows, so there is basically no need to spray pesticides or weeding when growing seawater rice.
I also saw a lot of official media writing that seawater rice cultivation does not require fertilization. I personally find this unbelievable. If you want the plants to grow well, fertilization should be necessary.
Finally, let’s talk about the taste of sea rice!
Because it grows on barren land, this will definitely affect its taste, but as the technology related to sea rice matures, this should not be a problem in the future.
Reference:
[1].https://doi.org/10.33 89%2Ffnut.2021.758547
[2].http://www.kepu.gov.cn/www/articl e/dtxw/407af03127d84e32ab4c8b0b00bff358
[3].http://www.xinh uanet.com/science/20230706/01a51977a33d45d08436eb603469604f/c.html