Chinese seeds can come in handy at critical moments!

Corn can also be infected with infectious diseases, but good quality corn varieties can be “spotless”.
At the "Discussion on Policies and Opinions" series of activities organized by the Beijing Association for Science and Technology on December 28, Zhao Jiuran, head of the Corn Expert Guidance Group of the Ministry of Agriculture and Rural Affairs and researcher at the Corn Research Institute of the Beijing Academy of Agricultural and Forestry Sciences, reviewed on the spot a story of "anti-epidemic" of good varieties that occurred this autumn.

Improved varieties to fight the epidemic
"Southern corn rust is an airborne fungal disease. The pathogen spores can spread over long distances from south to north along warm and humid air currents in summer." Zhao Jiuran said that corn rust occurs from time to time, but this year a rare large outbreak occurred in the summer corn areas of the Huanghuai and Haihe River regions.

Corn infected with rust is like a person's "overnight gray hair". At first, a small number of "yellow spots" appear on the leaves, which quickly spread all over the body, causing large areas of corn to die, severely reducing or even completely eliminating the yield. In the pictures shown by Zhao Jiuran, the infected corn in the autumn of 2021 is burnt yellow, while the rust-resistant varieties planted next to it are still lush and growing vigorously.

Report presentation pictures. Photo by Science and Technology Daily reporter Zhang Jiaxing

To resist infectious diseases, people rely on vaccination to gain immunity. What do plants rely on?

Zhao Jiuran revealed the secret: using disease-resistant genes to give corn disease-resistant "immunity". Over the years, Zhao Jiuran's team has completed the key "three steps" in one go, including selecting immune and highly rust-resistant corn germplasm, accurately locating and cloning rust-resistant genes, and transferring them to independent backbone strains.

"This breeding method of adding a special excellent trait to the original excellent varieties independently bred is called 'superior seed improvement'." Zhao Jiuran said that the superior seed improvement technology has enabled more than 20 varieties that were originally not resistant to rust to quickly achieve high resistance to rust. The proactive research on improved varieties has ensured that at the critical moment of the rust outbreak in the Huanghuaihai corn region this year, Chinese seeds were able to remain spotless in the "epidemic area."

More than just rust resistance——

"This year's Central Rural Work Conference and the Ministry of Agriculture and Rural Affairs both proposed to demonstrate and promote intercropping of corn and soybeans on a large scale." Zhao Jiuran said that to implement this task, it is necessary to make corn and soybeans resistant to the same herbicide, and the "superior seed improvement" technology has been put into practice again.

It is reported that Zhao Jiuran's team has cooperated with the team of Academician Deng Xingwang of Peking University to create a new corn germplasm with high resistance to imidazole herbicides (a commonly used herbicide for soybeans, but which has serious phytotoxicity to corn). This can simultaneously achieve the conversion and improvement of imidazole herbicide resistance of more than 20 approved excellent hybrid varieties, thereby realizing intercropping.

Chinese seeds can help at critical moments <br /> Based on the support of DNA fingerprint technology platform, the improvement of traits is one of the typical representatives of China's breeding capacity improvement.

Xu Shiwei, a researcher at the Chinese Academy of Agricultural Sciences and chief scientist of agricultural monitoring and early warning, said that China's breeding capacity is constantly improving. my country has formed a new mechanism for joint research by government, industry, academia and research, approved many varieties, achieved a good result of an average increase of 5% in yield per unit area, and realized a new round of variety replacement.

Especially during the 13th Five-Year Plan period, my country has established three national breeding and seed production bases in Hainan, Gansu and Sichuan, and built 52 large counties for hybrid seed production and 100 district and county seed production bases. The construction of these bases has played an important role in significantly improving the quality and quantity of China's seed production.

In response to the widespread misunderstanding that "China's seeds are heavily dependent on imports", Zheng Huaiguo, director of the Knowledge Management and Intelligence Research Center of the Institute of Data and Economics of the Beijing Academy of Agricultural and Forestry Sciences, and researcher, gave specific data. According to statistics from the Ministry of Agriculture and Rural Affairs, my country's self-sufficiency rate for rice and wheat varieties is 100%, corn is about 95%, and vegetable seeds are more than 87%. Only some high-end vegetable varieties such as broccoli are indeed dependent on foreign imports.

"In fact, our country's staple food varieties can be said to have achieved self-sufficiency and can meet the needs of our market," said Zheng Huaiguo.

Goal: A more advanced 4.0 era
The Central Rural Work Conference held from December 25 to 26 put forward requirements to vigorously promote the research and development of key core technologies in agriculture such as seed sources.

In this regard, experts at the meeting said that compared with foreign breeding technology, the world has gradually entered the 4.0 era of smart breeding, while my country is still in the 2.0 to 3.0 stage, and there are still a large number of key core technologies that need to be broken through.

"Developed countries have made significant progress in the discovery and functional analysis of major genes and the mechanisms of the formation of important traits." A relevant person in charge of the Beijing Municipal Bureau of Agriculture and Rural Affairs explained that the integration of biotechnology and artificial intelligence technology has enabled the selection and breeding of improved varieties to be refined, precise, intelligent, and functional, especially industrialized, which has greatly improved breeding efficiency.

In comparison, my country started late in combining breeding technology with information technology. "A number of key technologies need to be broken through, such as the key technology of intelligent phenotypic performance measurement, which can match key genes with phenotypes such as sweet taste one by one, no longer relying on manual work, but relying on sensors, infrared, Internet of Things hyperspectral and other technologies, and then establishing model analysis through big data integration to greatly improve breeding efficiency." Xu Shiwei said that my country is building a breeding platform based on artificial intelligence, which is still in the exploratory stage.