From the creation of materials to breeding and seed production, a rice seed is bred in this way

This is how an improved rice variety is bred (first-line research)

　　Our reporter Zhou Yajun

　　"People's Daily" (Version 06, February 7, 2023)

　　In April 2022, General Secretary Xi Jinping visited Hainan and came to the "brain" of the National Southern Breeding Research and Breeding Base - Sanya Yazhou Bay Seed Laboratory.

The general secretary said: "Only by grasping the seeds of China with one's own hands can China's rice bowl be stabilized and food security realized."

　　Nanfan, the repeated migration journey of a large number of agricultural workers.

From September to May of the following year, they come to Hainan from all over the world to take advantage of the unique tropical climate conditions here to carry out a series of scientific research activities such as crop seed breeding, which is where the name "Southern Breeding" comes from.

　　Right now, it is the season of southern blooming.

Let us follow a rice seed to observe how it will grow from material creation to breeding and seed production.

Sampling - Sanya, Hainan

It took 10 years of hard work to produce a good variety

　　Some have just been sown as seedlings, some are green and heading, and some are already golden and waiting to be harvested. When you walk into the Sanya South Breeding Base of China Seed Group, you can see the rice in various growth stages.

　　"Hainan's advantage is sufficient light and temperature resources, and we have to sow seeds here every two months." Shi Yitao, rice breeding assistant of China Seed Group, is a good player in the crop field, "If farmers know it, we will; farmers won't Yes, we understand too."

　　For a year, he guarded the experimental field like taking care of a child, and his broad face was tanned.

"Water frequently and observe carefully every day to prevent snails, birds and mice. I want every seedling to germinate and grow vigorously." Shi Yitao said.

　　Strong wind, strong rain and strong sun, this is the generalization of the local climate by Nanfan people.

　　Sowing seeds under the scorching sun, sometimes, you have to hide from the rain four or five times in half a day.

Whenever it rains, Shi Yitao is worried: When the seedlings were young, he was afraid that the heavy rain would wash up the nutritious soil and wash away the seedlings; The head of the ear is on the water surface, wading against the wind and rain again and again to drain the water, "Don't be afraid of danger, nothing is as important as keeping the seedlings."

　　In the corner of the experimental field, the iron fence is deeply embedded in the soil, and a small piece of paddy field has received special care.

"Specialized to prevent rats, afraid of chewing on materials." Shi Yitao gently opened the small iron door, walked through a section of field ridge, and saw tall and emerald green seedlings.

　　"These are the breeding materials R1607 with the low-cadmium gene introduced, and they are already in the tillering stage." Shi Yitao bowed his lower body and used tweezers to remove the leaves, about 1 cm long, and carefully put them into a deep-well plate. "I hope to take a sample at one time. will succeed."

　　From the summer of 2021 to the present, this batch of materials has been planted in Hainan for three consecutive seasons, plus one season in Hainan in the winter of 2020 and one season in Hubei in early 2021. Over two years of continuous hybridization, backcrossing, and self-crossing, it has been 5 years. generation.

Preliminary laboratory test data show that the genetic traits of the low cadmium gene have already appeared in the offspring.

　　"If there is no problem with the re-examination data, after maturity, we can select a trial-produced seed with the best growth and the best genetic data in the laboratory from the 2,000 plants." Shi Yitao said.

　　Just pick one, will it be too few?

　　"Don't underestimate it. The seed setting rate is very high. There are one or two thousand grains per plant, and the ears of rice are as long as half an arm. This is why the rice variety Quanyou 607 is favored by the market."

　　"If you compare Quanyou 607 to an excellent 'baby', then R1607 is like an excellent 'father'." Zhou Hua, director of rice testing of China Seed Group, said that R1607 not only aggregated 8 rice blast resistance genes, 3 lodging resistance genes, sheath blight resistance, cold resistance, submergence tolerance, nitrogen efficiency genes and 17 yield genes were aggregated.

Now after introducing the low-cadmium gene, even if the rice is planted in a field with excessive cadmium content, it will have low adsorption or insensitivity to cadmium.

　　How long does it take to breed an excellent variety like Quanyou 607?

　　"It took a full 10 years from breeding to approval!" Zheng Ruifeng, head of Quanyou 607's R&D team and director of rice breeding of China Seed Group, said that there is great uncertainty in creating new materials. "52 hybrid combinations have been made successively. In the end, only R1607 was bred."

　　The R&D team will then introduce bacterial blight resistance genes, rice planthopper resistance genes, aroma genes, etc., and continue to upgrade and transform, making R1607 an all-around champion, so that the "baby" born will be even better.

　　What is the most difficult part of breeding?

　　Zheng Ruifeng answered this way: If the varieties that show "leverage" are put on trial planting in other places, some unexpected situations may appear, such as not being resistant to high temperature, not resistant to low temperature, sometimes not resistant to lodging, not resistant to a certain disease, or Sensitive to a certain climate, "this will make all the previous efforts and investments return to zero."

　　Early research and development is difficult, but the heart is not too suspenseful. Once it enters large-scale production, the strings in the heart will be tightened. The larger the promotion area, the more worried it will be.

"If farmers fail to harvest food, we will have trouble sleeping and eating, and we will feel relieved when we harvest." Zheng Ruifeng said.

Testing——Wuhan, Hubei

Breeding experts put on "gene glasses"

　　In Wuhan City, Hubei Province, the genotyping laboratory of China Seed Group Life Science and Technology Center, the low-cadmium samples sent from the Sanya base finally ushered in the key experimental link-extracting DNA genetic material and conducting genetic analysis.

　　Zhang Xiaobo, the person in charge of the laboratory, tapped the button, and the vibrator, centrifuge, and PCR instrument were running one after another.

The data shows that the recovery rate of differential loci is 88.7%, and the recovery rate of the whole genome level reaches 97.5%.

　　What do these data mean?

"This shows that the low-cadmium gene has indeed been stably inherited into the offspring of R1607. After the upgraded version of R1607 matures, a new trial production process can be started." Zhang Xiaobo explained.

　　"During the breeding process, the laboratory and the experimental field are closely linked." Ye Rongjian, deputy director of the Technology Platform Department of the Science and Technology Center of China Seed Group, said that it is difficult to observe the genetic performance of the low-cadmium gene after introduction. "Is the cadmium absorbed into the rice grains?" , can’t be seen with the naked eye.”

　　"When we first created R1607, molecular biological breeding technology just started, and we followed the path of traditional hybrid breeding combined with molecular breeding-assisted selection. Now molecular marker detection and genomic breeding technology are very common. Put on a pair of glasses that can see through the function of genes." Zheng Ruifeng said that future intelligent breeding, relying on artificial intelligence, big data, and biotechnology, will be more efficient and accurate.

　　Of course, the powerful functions of this pair of "glasses" depend on breakthroughs in basic research.

"The reason why the low-cadmium gene introduction has achieved results in more than two years is because the functional sequence of the low-cadmium gene is very clear." Ye Rongjian introduced that there are about 50,000 genes predicted in rice, and about 4,000 genes have been cloned and their functions have been clarified so far. The functional cognition of a gene may take many years, and there is still a long way to go.

　　"The laboratory not only undertakes the task of detection and analysis, but also explores the mysteries of genes." Seed manager Nie Dongming pushed open the heavy security door, and the germplasm resource bank with more than 100,000 rice materials was presented in front of him.

Here, at a temperature of 4 degrees Celsius, the seeds enter a dormant state and can be safely stored for 5-10 years.

　　Zhou Hua said that the germplasm resource bank is a treasure house for creating breeding materials.

It was in Sanya that Academician Yuan Longping discovered the special material of wild rice sterile strain "wild beetle", which made a breakthrough in hybrid rice breeding.

　　The breakthrough of R1607 in rice blast resistance is also due to the credit of the germplasm resource bank.

"At that time, we were making a breakthrough in the technology of combating rice blast. I heard that the Chinese Academy of Sciences had discovered a gene with strong resistance, but the breeding experts did not have this material at hand. We went to the germplasm bank to search and found the original material. "Zheng Ruifeng introduced that this farm variety was used to cross and backcross with indica rice varieties, and a series of materials containing rice blast resistance genes were bred.

　　"If you lose something in nature, you may not be able to find it when you want to use it in the future. Now everyone has a deeper understanding of the importance of the germplasm bank." When the value and advantages of germplasm resources have not been tapped out, it is a kind of protection at the source.

　　Zhou Hua introduced that China Seed Group and Yazhou Bay Seed Laboratory jointly publish rankings for the country's first-class scientific research institutes and universities, and the industry-university-research collaboration integrates genetic resources. There are more than 10 topics in the rice field alone.

In addition to further cooperative research on low-cadmium genes, there are also cooperation on herbicide resistance and rice false smut resistance.

"The goal is to make excellent rice varieties full of treasures."

Seed Production——Hainan Oriental

1 mu of land for seed production can supply more than 100 mu of field

　　"Yanmei, throw me the seedlings!" "Okay, go ahead!" Without raising her head, Fu Yanmei released a bunch of green and tender rice seedlings, flying past eight or nine women bent over the paddy fields, and slashed across the paddy fields. An arc was precisely "cast" to Zeng Yabei's side.

　　On February 3, in Gancheng Town, Dongfang City, Hainan Province, rice planting and transplanting have been busy for more than a week after the Spring Festival.

The villagers cooperated skillfully, chasing after each other in planting rice seedlings in the field, and there were bursts of laughter from time to time.

　　Such busy and cheerful scenes often appear in the process of seed production.

The most attractive part of the whole seed production process is heading and flowering, also called powdering.

　　At the end of October last year, in this field, the reporter witnessed a scene of chasing fans.

The sky cleared, the temperature rose, and the male and female materials in the rice fields bloomed and pistils, and the small pale yellow flowers dotted with light green rice ears swayed gently in the breeze.

The 40-meter-long rope hangs on the ears of rice in an arc.

The two workers each held one end and walked forward quickly in parallel. Where the rope passed, the ears of rice touched, the stamens shook, and the pollen floated to the pistils of the female parent.

　　Wang Shiming, general manager of Hainan Nongle Nanfan Technology Co., Ltd., said: "Breeding means bringing a bag of seeds and carrying a bag of seeds back. Seed production is different. One mu of land for seed production can be used for more than 100 mu of field."

　　There are many seed production processes, so it is necessary to reverse the construction period so that the parents can meet each other in this flowering period.

For example, it takes 100 days for the male parent of Quanyou 607 to flower, and 80 days for the female parent, so the male parent needs to be sown 20 days in advance; after that, the leaf stage is constantly observed, the flowering stage is analyzed, and water and fertilizer are sometimes adjusted to ensure Flowering meet.

　　"Manual powdering can improve the seed setting rate of hybrid rice." Wang Shiming introduced that many years ago, the "seed production army" from Pingxiang City, Jiangxi Province used to have as many as 100,000 people in Hainan.

In recent years, the country has revitalized the seed industry, and Pingxiang has also introduced measures such as subsidies for large seed producers and superimposed grain subsidies.

Encouraged by this, many Jiangxi farmers who produced seeds in Hainan have returned to their hometowns to develop.

　　"Raising seedlings and planting seedlings, earing and pollination, harvesting and drying seeds, selecting and packaging seeds, I can do it when I was young." Wang Shiming has followed his parents to Hainan to produce seeds for more than 20 years. His skin is dark and red, and he speaks slowly.

Dongfang City, where he lives, will be recognized as a national-level seed production county in 2022, with millions of acres of grateful plain land. Time to plant seedlings."

　　Affected by rising land rent and labor costs, rice seed production in Hainan has been moving westward, from Sanya City to Ledong Li Autonomous County, and then to Dongfang City.

"The average annual land transfer per mu in the East is 1,300 yuan, while in Sanya it has already exceeded 3,500 yuan." Wang Shiming said.

　　In the middle and late September of 2022, Wen Mincao, deputy manager of the production department of Zhongzhong Agricultural Science and Technology Company, received an urgent task. When the seed production area of ​​Quanyou 607 Hainan increased from the original 6,000 to 7,000 mu to more than 20,000 mu, his head was buzzing. Hum, where can I find the manufacturer and production base?

　　Zhongzhong implements an order system, and plans are given to manufacturers and professional teams all over the country every year.

However, the farming season in the inland area in winter has passed, and it is difficult to produce seeds. Although Hainan can produce seeds, it is also the season of melons and vegetables in winter.

　　Thanks to Wang Shiming's multiple contacts, Wen Mincao reached an agreement on 6,000 mu of land in just one week, and finally took a breather.

"The large seed production county supports the integration of production, processing, storage, packaging and logistics. With favorable policies, we have signed a cooperation framework for the integration of production and supply chains with local manufacturers. We will produce and pack on the spot and send them to the market. stored."

　　All the hard work is worth it.

　　In the middle and lower reaches of the Yangtze River, farmers who have tasted the sweetness have long thought about good seeds.

In Shilou Village, Wudian Town, Zaoyang City, Hubei Province, Chen Bangguo, a major grain grower, finished planting winter wheat and called Qiu Yunze, a seed distributor in Wudian Town, within three or two days.

　　"Good seeds are in high demand! When I was trying to plant Quanyou 607, Lao Qiu came to sell it to me. He guaranteed that the seeds would not be good enough to compensate me for the yield. As a result, two to three hundred catties of rice were sown per mu of land. I Happy to invite Lao Qiu to dinner!" Chen Bangguo said.

　　"In the early stage, we will build a model field display, and invite large households to observe the harvest and yield on the spot, so that more farmers can see the comparative advantages of varieties. In the later stage, we will collect information on high-yielding farmers, make promotional posters, and organize seedling viewing meetings when the seedlings are heading. Expand the influence." Speaking of the promotion experience of good seeds, Wang Hanyong, the deputy sales manager of Hubei District of China Seed Group, talked endlessly.

　　The field of hope continues season by season, and the story of a good seed will continue to be told.

　　Planning for this issue: Yin Xinyu, Wu Yan, Cheng Juxin