Around 1,500 rice seeds that traveled with China's Chang'e-5 spacecraft to the moon and back have been transplanted to the field in southern China, allowing scientists to study their gene mutations and create higher-yielding and better nutritional varieties.
The 40 grams of rice seedlings traveled last November with China's Chang'e-5 moon probe, named after the lunar goddess in Chinese folklore, for a 23-day space journey. Upon their return to Earth, they were initially planted at a breeding center of the South China Agricultural University in Guangdong Province, before being transplanted in late March.
Since the 1920s, seeds have been exposed to radiation or chemicals by scientists to induce greater yield, productivity and adaptability to climate change. More than 2,500 varieties of plants bred through mutagenesis have been officially released, according to the Food and Agriculture Organization.
Space is a new setting to test plant breeding, as strong cosmic rays, vacuums, microgravity and low levels of geomagnetic interference exert a great impact on plant growth and development, which eventually affects plant yield. Since the 1960s, countries from the US to Russia and Japan have all tried breeding seeds and growing plants on the space station to study plant mutations while adding fresh food to the astronauts' diet.
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The new space-bred rice seedlings were "a breakthrough of mutation rice breeding experiments in deep space," said Chen Zhiqiang, director of the lab in an interview with the Xinhua News Agency. These seeds contain 40,000 genes and the mutations after deep-space exposure can be tracked in a targeted way to find which good genes can be used for breeding, according to the researchers.
"On the ground, researchers use radiation and heavy ions to simulate the microgravity environment to carry out seed mutation. The deep space environment is extremely unique and is expected to produce even stronger genetic effects," said Guo Tao, deputy director of the center.
The rice is expected to be harvested at the end of June and then sown for a second generation, according to Guo. Promising characteristics of seeds can be stabilized after four to five generations, and then new rice varieties with high quality and high yield can be selected, he said.
The space-bred seeds are important to help China’s poverty alleviation efforts and improvement of farmers’ income. The country approved its first space rice, known as Huahang 1, in 2003, which was planted on 333,300 hectares of land in southern China, according to the China Daily.