Scientists harvest nutrient-rich rice grown in space
by Simon Mansfield
Sydney, Australia (SPX) Nov 11, 2024

At a crop breeding center in Shanghai, researchers have successfully harvested rice that was cultivated from seeds initially grown on China's space station Tiangong, also known as "Heavenly Palace." The rice plants have completed a full growth cycle on Earth, maturing after more than 100 days since planting.

This space-to-ground experiment began with six rice seeds sent into orbit in 2022 on the Wentian spacecraft. Taikonauts onboard Tiangong bred these seeds into 59, which they returned to Earth. Researchers then selected high-quality seeds, cultivating them under controlled climate conditions and yielding around 10,000 new seeds. A portion of these were planted in open fields to continue growth trials.

According to Zheng Huiqiong, a lead researcher at the Chinese Academy of Sciences' Center for Excellence in Molecular Plant Sciences, the experiment represents three "generations" of rice plants, with seeds in space representing the first, those in artificial climates as the second, and the final crop as the third. Zheng shared that the team's findings suggest space-grown seeds can reproduce effectively on Earth, hinting at potential for future space agriculture.

Space breeding, the method used in this experiment, exposes seeds to cosmic radiation and microgravity, inducing gene mutations. These mutations are carefully assessed upon the seeds' return to Earth, sometimes resulting in advantageous traits like shorter growth times, improved disease resistance, and higher yields.

Zhao Hui, an expert with the China Academy of Space Technology, emphasized the safety of space-grown food, explaining that unlike genetically modified organisms, space-bred seeds naturally mutate without introducing foreign genes.

Enhanced Sweetness and Nutritional Value
Zheng highlighted that the space-grown rice possesses unique traits, such as a higher sugar content, with glucose and fructose levels estimated to be five to six times greater than standard rice. "We estimated that they are approximately five or six times higher," Zheng stated. The space-bred rice also showed a slight increase in protein content. "That means space-bred rice tastes sweeter and has more energy," she added.

However, the space-bred rice has sparser leaves, which complicates dense planting. Researchers are planning further studies to understand these leaf density traits and explore possible genetic modifications.

The Tiangong rice experiment marked a milestone for crop science, as it was the first time rice completed a full life cycle - from seed germination to reproduction - in orbit. Similar orbital cultivation had previously been achieved with plants like Arabidopsis, canola, peas, and wheat on the International Space Station.

Zheng explained that growing rice in the space station's vacuum environment required a fully enclosed setup with carefully controlled light, water, and gas. Since rice thrives on sunlight, the artificial lighting used had to be meticulously managed to support photosynthesis.

China has long pursued advancements in space-based agriculture, with its first space-breeding experiment dating back to 1987. Since then, it has sent seeds from hundreds of plant species into orbit using both satellites and Shenzhou missions, exposing them to the unique conditions of space for agricultural research.

In the ongoing study, scientists aim to analyze space-grown rice's yield and agronomic properties, supporting food security efforts for future space missions.

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China Manned Space Agency
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