(LI MIN / CHINA DAILY)
Humanity’s desire for high-yielding crops is as old as civilization itself.
According to the Chinese Academy of Social Sciences’ Institute of Ethnic Literature, 41 of China’s 56 ethnic groups have their own creation myths about fertile seeds.
The Dong ethnic group believes that seeds were bestowed by deities showing mortals compassion, while according to Wa ethnic group folklore they were spat out by a world-devouring snake slain by the Heaven God.
Now, modern technologies have produced quality seeds from an equally fantastic source — outer space.
These seeds have produced crops spanning tomato vines that can sprawl across 150 square meters of land and bear 10,000 fruits, and giant black-eyed pea sprouts nearly a meter long, according to the China Aerospace Science and Technology Corp.
This has been achieved through space-induced mutation breeding, or space mutagenesis.
Hundreds of space crop varieties have been planted across China. This key pillar supporting food security represents an innovative approach to improving farmers’ yields and combating rural poverty.
The International Atomic Energy Agency defines space mutagenesis as a technique in which seeds brought into space are exposed to strong cosmic rays — high-energy particles traveling close to the speed of light — along with such conditions as vacuums, microgravity and low levels of geomagnetic interference.
It does not involve transferring genes between organisms, unlike genetically modified food. Instead, it generates random but potentially useful traits by using a plant’s genetic material, mimicking the natural process of spontaneous mutation, albeit at a significantly accelerated rate, the agency said.
Since the 1920s, scientists have exposed seeds to radiation or chemicals to induce greater yield, stability and climate change adaptability. More than 2,500 varieties of plants bred through mutagenesis have been officially released, according to the Food and Agriculture Organization of the United Nations.
Space is a new setting for this time-tested breeding method, and the IAEA, FAO and the World Health Organization consider space crops safe to consume upon passing rigorous testing and approval processes.
In the 1960s, the United States and the Soviet Union conducted space mutagenesis for scientific research and to make astronauts’ life in space more sustainable.
“However, no country has turned this into a full scale, modern agricultural industry like China has done,” said Guo Rui, director of the Shaanxi Province Engineering Research Center for Plant Space Breeding.
In 2018, China’s space breeding industry had a direct economic impact of more than 200 billion yuan (US$30.4 billion) and produced over 1.3 million tons of food, according to CASTC.
More than 200 space plant and fruit varieties, including rice, wheat, maize, soybeans, cotton and tomatoes have been approved for planting by regulatory bodies, with over 3,000 more in development. In 2018, the total plantation area for space crops approved in China exceeded 2.4 million hectares — roughly the size of New Hampshire in the United States.
Guo said: “China is the world leader in breeding plants in space, partly due to the country’s rapid rise as a world space power.
“But more important, we are pursuing this technology vigorously because we need to solve many strategic challenges, such as feeding a populous nation with limited arable land supply, as well as modernizing our agricultural sector and ensuring food security.”
Chengcheng county in Shaanxi province is home to Piperis dahongpao, a spice commonly known as big red robe peppercorn, widely employed in Chinese cuisine.
It has been used since the Han Dynasty (202 BC-220 AD) for cooking, medicine, rituals and palace decorations, according to the Kunming Institute of Botany, Chinese Academy of Sciences.
However, it has a notoriously low yield and its thorny stems make it difficult to harvest. For centuries, it was considered a “tribute spice” for the privileged, the best-known being Empress Dou of the Han Dynasty, who decorated her chamber with it to signify fertility and prestige.
Guo said: “A laborer can only pick about 7.5 kilograms of this peppercorn per day, and after it is dried in the sun, less than 2 kg is left.”
Farmers from Tianjiazhai village, Xining, capital of Qinghai province, harvest beetroot bred in space at Qinghai Qianziyuan Space Plant Exhibition Park. (PHOTO PROVIDED TO CHINA DAILY)
In 2016, Guo and his team sent spice seeds into orbit for 12 days aboard the Shijian-10 recoverable science satellite.
Aiming to create a new peppercorn variety with stronger resistance to wind and disease, the team discovered something far more exciting — the thorns on the stems had disappeared.
“Generating unexpected new traits is one of the main features of space-induced mutation breeding,” Guo said.
Breeding labs can now effectively produce some space conditions, but replicating them all is impractical and costly, Guo said. Moreover, mutating seeds in space may produce surprising traits more successfully. “Space is like a super-lab for breeding new plants,” he added.
Liu Luxiang, deputy director of the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, at a public lecture said that while promising, the way in which space affects plant seeds is extremely complex and difficult to control and evaluate.
“Only a tiny fraction of seeds exposed to space will have mutations, and not all of them will produce desirable traits,” he said. Consequently, sending seeds into space is merely the start of creating a new variety.
Scientists sometimes cross-breed space crops to create hybrids that inherit favorable traits, Liu said. “Ground tests can be a very arduous and complicated process that typically takes at least four years to complete,” he added.
Guo said: “Space crops have played a major role in alleviating poverty, developing local economies and creating unique products.”
Located at the heart of the Qinghai-Tibetan Plateau, Nyemo — “ear of grain” in the Tibetan language — is home to Tibetan incense and has a rich history of farming and cultivation.
However, decades of environmental degradation left land in the remote county barren, with more than 5,100 impoverished villagers in 2016, according to the Office of Beijing Municipal Leading Group for Poverty Reduction Cooperation and Assistance.
To reduce poverty and restore land fertility, the Beijing municipal government and county authorities introduced space plants to the locals.
Companies also invested in computerized greenhouses in Nyemo to grow peppers, tomatoes, cucumbers, watermelons and nine other crops that can survive the arid plateau. Last year, space produce sales exceeded 400,000 yuan, with more than 25 percent of the earnings distributed among 98 poverty-stricken families, the office said.
“Not only have I learned new skills at the space plant greenhouses, I have found a way to get rich and have also taken on an apprentice,” said Phuntsok Tsering, a villager from Nyemo.
Tutored by scientists on how to grow tomatoes using mineral nutrient solutions rather than soil, he now earns at least 3,000 yuan per month.
By October, CASTC had used space crop agriculture to eliminate poverty in 21 villages across nine provinces, including 30,000 people in Yang county, Shaanxi province.
Chen Zhiqiang, director of the National Engineering Research Center of Plant Space Breeding, said high-quality space rice varieties were essential to safeguarding national food security and alleviating poverty in Guangdong province.
In 2003, China approved and planted its first space rice — Huahang-1 — on 333,300 hectares of land in the south. From 2010 to 2012, the center’s crops covered a plantation area exceeding 621,360 hectares, raising farmers’ earnings nearly
1 billion yuan.
Huahang simiao, a disease-resistant space rice variety, has been especially popular in Boluo county, Guangdong. High yield and highly flavorsome, farmers sold it for 250 yuan per 50 kg, 150 yuan more than others, according to the local agricultural bureau.
Chen said: “Seeing the smiles of my farmer friends when they have a good harvest is the most satisfying reward to me.”
Since China launched its first seed samples into space on Aug 5, 1987, Chinese scientists have used satellites and spacecraft to send more than 30 batches of seeds, according to CASTC.
But apart from the Shijian-8 recoverable science satellite, designed specifically for breeding plants in space and launched in 2006, all such missions employed instruments for other purposes, severely limiting the quantity sent into orbit.
“Cost and accessibility are some of the biggest bottleneck issues for breeding plants in space,” said Wang Weidong, deputy general manager of Beijing-based aerospace company Azspace, specializing in spacecraft re-entry technologies and services.
Scientists send multiple batches into orbit to increase the success rate of generating mutations. However, the cost-effectiveness of such missions is “hard to manage” due to a shortage of inventory and retrievable space instruments, she said.
“A prosperous commercial spaceflight industry can provide more launch opportunities and services, reducing the cost of space travel and greatly lowering the entry barrier for breeding plants in space. This will enable such breeding to become a more accessible and mainstream technology,” Wang said.
Zhang Jianwei, a researcher at the Institute of Isotope Research, Henan Academy of Sciences, said that making a new wheat variety using mutation breeding would typically need 3,000 seeds weighing about 135 grams.
It costs about 3,000 yuan to send 1 gram of material into space; sending a sample package of seeds would cost 405,000 yuan, Zhang said.
“Space is an interesting platform for mutation breeding, but as this may not be very cost-efficient, many researchers still prefer the far cheaper, more accessible and time-tested method of using labs,” he said.
“If China’s commercial space industry can grow to the point where cheap and available flights are possible, it will push breeding plants in space to new heights,” Wang said.
