The upcoming Shenzhou-23 spaceflight mission will experiment cultivating two consecutive generations of rice in orbit, according to the Technology and Engineering Center for Space Utilization of the Chinese Academy of Sciences.
China is sending rice seeds along with astronauts to its space station Tiangong via the Shenzhou-23 spacecraft, scheduled to be launched on Sunday.
The new rice experiment, if successful, will mark the first complete growth cycle from seed to new seed grown in space, then to a second generation of space seeds, opening possibilities for in-situ food production on future lunar base and deep-space missions.
In 2022, six rice seeds spent 120 days aboard Tiangong, flowering and producing 59 offspring grains. The upcoming mission upgrades that effort by adding a second new generation.
In microgravity, plants lose their sense of direction and rice seedlings tend to grow erratically. Scientists have developed a method of using directional lighting to guide upright growth. Rice's self-pollination also helps overcome the challenge of pollen failing to settle naturally in microgravity.
However, rice cultivation in space still faces a series of challenges, like disrupted flowering times, slower development cycles, and reduced seed vigor.
The experiment will compare two cultivation methods to explore answers to these challenges and find the best fit for the space station's confined environment - the conventional sexual reproduction through flowering and seed propagation, and the asexual reproduction which involves ratoon rice that regrows from retained roots after harvest.
Another batch of rice seeds will undergo five months of exposure to space radiation and varying gravity levels in external and internal experiment boxes, potentially generating mutations that could yield valuable germplasm resources for breeding new varieties.
Shenzhou-23 to grow second-generation space-faring rice seeds
